U.S. patent application number 16/274635 was filed with the patent office on 2019-06-13 for display device.
The applicant listed for this patent is Japan Display Inc.. Invention is credited to Tadayoshi KATSUTA, Gen KOIDE, Hiroshi MIZUHASHI.
Application Number | 20190179460 16/274635 |
Document ID | / |
Family ID | 59786646 |
Filed Date | 2019-06-13 |
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United States Patent
Application |
20190179460 |
Kind Code |
A1 |
MIZUHASHI; Hiroshi ; et
al. |
June 13, 2019 |
DISPLAY DEVICE
Abstract
Provided is a touch detection function-equipped display device
that can be manufactured while suppressing an increase of price. A
display device is provided with a pixel array including a plurality
of pixels arranged in a matrix form, and drive electrodes each of
which is arranged to extend in a first direction in the pixel
array. A drive signal is supplied to a first area in a first drive
electrode among the drive electrodes, and a ground voltage is
supplied to a second area extending in the first direction with
respect to the first area to generate a magnetic field in the first
drive electrode according to the drive signal at a time of
detecting an external proximity object.
Inventors: |
MIZUHASHI; Hiroshi; (Tokyo,
JP) ; KOIDE; Gen; (Tokyo, JP) ; KATSUTA;
Tadayoshi; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Japan Display Inc. |
Tokyo |
|
JP |
|
|
Family ID: |
59786646 |
Appl. No.: |
16/274635 |
Filed: |
February 13, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15448062 |
Mar 2, 2017 |
10228809 |
|
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16274635 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/0446 20190501;
G02F 1/133514 20130101; G02F 1/136286 20130101; G06F 3/046
20130101; G06F 3/0442 20190501; G02F 1/13338 20130101; G06F 3/047
20130101; G02F 1/1368 20130101; G02F 2001/133302 20130101; G06F
3/03545 20130101; G06F 3/044 20130101; G06F 3/0412 20130101; G06F
3/0416 20130101; G02F 1/134336 20130101; G06F 3/04166 20190501;
G06F 2203/04106 20130101; G06F 2203/04108 20130101 |
International
Class: |
G06F 3/046 20060101
G06F003/046; G06F 3/041 20060101 G06F003/041; G02F 1/1333 20060101
G02F001/1333; G02F 1/1362 20060101 G02F001/1362; G06F 3/044
20060101 G06F003/044; G06F 3/0354 20060101 G06F003/0354; G06F 3/047
20060101 G06F003/047; G02F 1/1343 20060101 G02F001/1343 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 10, 2016 |
JP |
2016-046778 |
Claims
1. A display device comprising: a pixel array including a plurality
of pixels arranged in a matrix form; a plurality of drive
electrodes each of which extends in a first direction and is
arranged in a second direction intersecting the first direction in
a detection area for detecting an external proximity object; a
plurality of detection electrodes each of which extends in the
second direction and is arranged in the first direction in the
detection area, a first drive wiring extending in the second
direction so as to face to one end portions of the plurality of
drive electrodes and providing an AC voltage to the one end
portions of the drive electrodes; a second drive wiring extending
in the second direction so as to face to the other end portions of
the plurality of drive electrodes and providing an AC voltage to
the other end portions of the drive electrodes; a first reference
voltage wiring extending in the second direction so as to face to
the one end portions of the plurality of drive electrodes and
providing a first reference voltage to the drive electrodes,
wherein the first reference voltage wiring is located farther from
the one end portions of the plurality of drive electrodes than the
first drive wiring; a second reference voltage wiring extending in
the second direction so as to face to the other end portions of the
plurality of drive electrodes and providing a second reference
voltage to the drive electrodes, wherein the second reference
voltage wiring is located farther from the other end portions of
the plurality of drive electrodes than the second drive wiring; a
plurality of first switch circuit coupling the one end portions of
the driving electrodes to one of the first drive wiring and the
first reference voltage wiring; and a plurality of second switch
circuit coupling the other end portions of the driving electrodes
to one of the second drive wiring and the second reference voltage
wiring.
2. The display device according to claim 1, wherein the plurality
of drive electrodes includes a drive electrode of which the other
end portion is coupled to the first reference voltage wiring while
a one end portion of the drive electrode is coupled to the first
drive wiring by a first switch circuit, and of which the one end
portion is coupled to the second reference voltage wiring while the
other end portion of the drive electrode is coupled to the second
drive wiring by a second switch circuit.
3. The display device according to claim 2, wherein a drive
electrode generates a magnetic field according to the AC voltage at
time of detecting the external proximity object, and the detection
electrodes detects a magnetic field generated by the external
proximity object in response to the magnetic field generated by the
drive electrode.
4. The display device according to claim 3, wherein the plurality
of drive electrodes are arranged in parallel to each other, the
plurality of drive electrodes including a second drive electrode is
arranged to be proximate to a first drive electrode, and a one end
portion of the first drive electrode is coupled to the first drive
wiring and a one end portion of the second drive electrode is
coupled to the second reference voltage wiring at time of detecting
the external proximity object, and the other end portion of the
first drive electrode is coupled to the first reference voltage and
the other end portion of the second drive electrode is coupled to
the second drive wiring at the time of detecting the external
proximity object, whereby the magnetic field generated by the first
drive electrode and the magnetic field generated by the second
electrode are superimposed on each other in an area between the
first drive electrode and the second drive electrode at the time of
detecting the external proximity object.
5. The display device according to claim 4, wherein a direction of
a current flowing in the second drive electrode is an opposite
direction to a direction of current flowing in the first drive
electrode at the time of detecting the external proximity
object.
6. The display device according to claim 5, wherein the plurality
of drive electrodes includes a third drive electrode which is
arranged between the first drive electrode and the second drive
electrode.
7. The display device according to claim 6, wherein a plurality of
stages of an operation of detecting the external proximity object
is executed during a display period for one frame in the pixel
array, a number of the third drive wirings is set to a
predetermined value at a predetermined stage, and the number of
third drive wirings is set to be smaller than the predetermined
value at a stage after the predetermined stage.
8. The display device according to claim 6, wherein the first drive
electrode includes a plurality of drive electrodes arranged to be
adjacent to each other, and the second drive electrode includes a
plurality of drive electrodes arranged to be adjacent to each
other.
9. The display device according to claim 3, further comprising: A
plurality of signal lines, which supply signals to the plurality of
pixels at time of display, and a plurality of drive lines which
intersect the plurality of signal lines are arranged in the pixel
array, the plurality of drive electrodes include the plurality of
drive lines, and the plurality of detection electrodes include the
plurality of signal lines.
10. The display device according to claim 3, wherein the pixel
array includes a first substrate on which a plurality of signal
wirings are formed and a layer which is interposed between the
first substrate and a second substrate arranged to oppose the first
substrate and is displaced depending on signals that need to be
displayed, the plurality of drive electrodes include the plurality
of signal wirings formed on the first substrate, and the plurality
of detection electrodes include a signal wiring formed on the
second substrate.
11. The display device according to claim 3, wherein the pixel
array includes a plurality of signal lines, which are arranged
along each column of the pixel array and supply signals to the
plurality of pixels, and a plurality of scan lines which are
arranged along each row of the pixel array and supply a scan signal
to select the pixel arranged in the row, and the plurality of drive
electrodes include the plurality of signal lines or the plurality
of scan lines.
12. The display device according to claim 11, further comprising: a
plurality of matrix electrodes which are arranged in a dot matrix
form in the pixel array; and a plurality of detection signal lines
which are connected to the plurality of matrix electrodes, wherein
the plurality of detection signal lines are arranged in parallel to
the plurality of signal lines and detect the external proximity
object based on a change of a charge amount in the matrix
electrodes.
13. The display device according to claim 12, further comprising: a
first substrate on which the plurality of signal lines, the
plurality of scan lines, the plurality of detection signal lines,
and the plurality of matrix electrodes are formed; and a second
substrate which is arranged to oppose the first substrate with a
layer, displaced depending on the signals that need to be
displayed, interposed therebetween, wherein the plurality of
detection electrodes include a plurality of signal wirings formed
on the second substrate.
14. The display device according to claim 3, further comprising: a
control circuit coupled to the first drive wiring, the second drive
wiring, the first reference voltage wiring and the second reference
voltage wiring, providing the AC voltage to the first drive wiring
and the second drive wiring and providing the first reference
voltage and the second reference voltage to the first drive wiring
and the second drive wiring at time of detecting the external
proximity object.
15. The display device according to claim 14, wherein the plurality
of drive electrodes includes a first drive electrode having the
other end portion coupled to the first reference voltage wiring
while a one end portion of the first drive electrode is coupled to
the first drive wiring by a first switch circuit, and wherein the
plurality of drive electrodes includes a second drive electrode
having a one end portion coupled to the second reference voltage
wiring while the other end portion of the second drive electrode is
coupled to the second drive wiring by a second switch circuit.
16. The display device according to claim 15, wherein the plurality
of drive electrodes includes a third drive electrode which is
arranged between the first drive electrode and the second drive
electrode, and the third drive electrode is isolated from the first
drive wiring and the second drive wiring or from the first
reference voltage wiring and the second reference voltage
wiring.
17. The display device according to claim 15, wherein the third
drive electrode is isolated from the first drive wiring, the second
drive wiring, the first reference voltage wiring and the second
reference voltage wiring.
18. A display device comprising: a pixel array including a
plurality of pixels arranged in a matrix form; a plurality of drive
electrodes each of which extends in a first direction and is
arranged on a second direction intersecting the first direction in
a detection area for detecting an external proximity object; a
plurality of detection electrodes each of which extends in the
second direction and is arranged in the first direction in the
detection area; a first drive wiring extending in the second
direction so as to face to one end portions of the plurality of
drive electrodes; a second drive wiring extending in the second
direction so as to face to the other end portions of the plurality
of drive electrodes; a first reference wiring extending in the
second direction so as to face to the other end portions of the
plurality of drive electrodes; a second reference wiring extending
in the second direction so as to face to the one end portions of
the plurality of drive electrodes; a plurality of first switch
circuit coupling among the one end portions of the driving
electrodes, the first drive wiring and the second reference wiring
and a plurality of second switch circuit coupling among the other
end portions of the driving electrodes, the second drive wiring and
the first reference wiring, wherein the plurality of drive
electrode includes a first drive electrode and a second drive
electrode in which currents follow at time of detecting the
external proximity object.
19. The display device according to claim 18, wherein a direction
of a current flowing in the second drive electrode is an opposite
direction to a direction of current flowing in the first drive
electrode at the time of detecting the external proximity object.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of U.S.
application Ser. No. 15/448,062, filed Mar. 2, 2017, which
application claims priority from Japanese Patent Application No.
2016-046778 filed on Mar. 10, 2016, the content of which is hereby
incorporated by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to a display device, and
particularly to a touch detection function-equipped display device
which is capable of detecting an external proximity object.
BACKGROUND OF THE INVENTION
[0003] Recently, a focus has been placed on a touch detection
device, a so-called touch panel, which is capable of detecting an
external proximity object. The touch panel is provided as a touch
detection function-equipped display device in the state of being
mounted on a display device, for example, a liquid crystal display
device, or being integrated with the liquid crystal display
device.
[0004] The external proximity object includes, for example, a touch
panel which allows a pen to be used. By allowing the pen to be
used, for example, it is possible to designate a small area or
input a handwritten letter. There are various types of techniques
to detect touch by the pen. One of the various types of techniques
is an electromagnetic induction system. This electromagnetic
induction system can realize a high accuracy and a high writing
pressure detection accuracy, also realize a hovering detection
function in which the external proximity object is spaced apart
from a touch panel surface, and so is an effective technique as the
technique of detecting the touch by the pen.
[0005] In addition, there is also a touch panel which allows a
finger to be used as the external proximity object. It is
unnecessary to prepare a pen or the like when it is possible to use
the finger, which allows simplicity and convenience. For example,
various button images and the like are displayed on a touch
detection function-equipped display device, and the proximity of
the finger to the button image is detected by the touch panel.
Accordingly, it is possible to use the touch panel instead of a
general mechanical button. Such a touch detection function-equipped
display device does not necessarily require an information input
means such as a keyboard and a mouse, and so tends to be widely
used in portable information terminals or the like such as a mobile
phone as well as a computer.
[0006] There are also various types of technique to detect the
touch by the finger. For example, there are several systems such as
an optical type, a resistance type, and a capacitance system. Among
them, the capacitive system has a relatively simple structure,
consumes low power, and so has been used in a portable information
terminal or the like.
[0007] The touch panel that allows the use of the finger is simple
and convenient, but it is not easy to designate a small area using
the finger, for example. Thus, desired is a touch panel which
allows both a pen and a finger to be used.
[0008] Touch detection techniques using the electromagnetic
induction system are described in, for example, Japanese Patent
Application Laid-open No. 10-49301 (Patent Document 1), Japanese
Patent Application Laid-open No. 2005-352572 (Patent Document 2),
and Japanese Patent Application Laid-open No. 2006-163745 (Patent
Document 3).
SUMMARY OF THE INVENTION
[0009] A display device according to the present invention
comprises: a pixel array which includes a plurality of pixels
arranged in a matrix form; a plurality of drive wirings each of
which is arranged to extend in a first direction in the pixel
array; and a plurality of detection wirings which are arranged to
extend in a second direction intersecting the first direction in
the pixel array. Also, a periodically changing magnetic field drive
signal is supplied to a first area in a first drive wiring among
the plurality of drive wirings, and a reference signal is supplied
to a second area extending in the first direction with respect to
the first area so as to generate a magnetic field around the first
drive wiring according to the magnetic field drive signal at a time
of detecting an external proximity object. Further, the magnetic
field generated by the external proximity object depending on the
magnetic field generated around the first drive wiring is detected
by the plurality of detection wirings.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0010] FIG. 1 is an explanatory diagram illustrating a relationship
between an electronic device including a touch detection
function-equipped display device and a pen;
[0011] FIG. 2A is an explanatory diagrams illustrating a principle
of an electromagnetic induction system;
[0012] FIG. 2B is an explanatory diagrams illustrating a principle
of an electromagnetic induction system;
[0013] FIG. 3A is a waveform diagram illustrating a principle of
the electromagnetic induction system;
[0014] FIG. 3B is a waveform diagram illustrating a principle of
the electromagnetic induction system;
[0015] FIG. 4A is a plan view schematically illustrating a
configuration of a display device according to an embodiment;
[0016] FIG. 4B is a cross-sectional view schematically illustrating
a configuration of a display device according to an embodiment;
[0017] FIG. 5A is an explanatory diagram illustrating a principle
of a capacitance system;
[0018] FIG. 5B is an explanatory diagram illustrating a principle
of a capacitance system;
[0019] FIG. 5C is an explanatory diagram illustrating a principle
of a capacitance system;
[0020] FIG. 6A is a cross-sectional view illustrating a schematic
cross section of the display device;
[0021] FIG. 6B is a cross-sectional view illustrating a schematic
cross section of the display device;
[0022] FIG. 7 is a plan view illustrating a magnetic field
generation coil and a magnetic field detection coil;
[0023] FIG. 8 is a block diagram illustrating a configuration of a
display device according to a first embodiment;
[0024] FIG. 9 is a plan view illustrating a configuration of a
module of the display device according to the first embodiment;
[0025] FIG. 10 is a plan view illustrating a configuration of a
display panel of the display device according to the first
embodiment;
[0026] FIG. 11 is a cross-sectional view illustrating a
configuration of the display device according to the first
embodiment;
[0027] FIG. 12 is a circuit diagram illustrating a circuit
configuration of the display panel of the display device according
to the first embodiment;
[0028] FIG. 13A is an explanatory diagram illustrating a touch
detection operation of the display device according to the first
embodiment;
[0029] FIG. 13B is an explanatory diagram illustrating a touch
detection operation of the display device according to the first
embodiment;
[0030] FIG. 14 is a block diagram illustrating a configuration of a
selection drive circuit of the display device according to the
first embodiment;
[0031] FIG. 15A is a waveform diagram illustrating a waveform in a
magnetic field generation period of the display device according to
the first embodiment;
[0032] FIG. 15B is a waveform diagram illustrating a waveform in a
magnetic field generation period of the display device according to
the first embodiment;
[0033] FIG. 15C is a waveform diagram illustrating a waveform in a
magnetic field generation period of the display device according to
the first embodiment;
[0034] FIG. 16 is a schematic plan view illustrating a magnetic
field touch detection operation of the display device according to
the first embodiment;
[0035] FIG. 17 is a schematic plan view illustrating the magnetic
field touch detection operation of the display device according to
the first embodiment;
[0036] FIG. 18 is a schematic plan view illustrating an electric
field touch detection operation of the display device according to
the first embodiment;
[0037] FIG. 19 is a plan view schematically illustrating a
configuration of the display device according to the first
embodiment;
[0038] FIG. 20 is a perspective view schematically illustrating a
configuration of the display device according to the first
embodiment;
[0039] FIG. 21 is a perspective view schematically illustrating a
configuration of a display device according to a modified example
of the first embodiment;
[0040] FIG. 22 is a plan view illustrating a configuration of a
display device according to a second embodiment;
[0041] FIG. 23 is a plan view illustrating an operation of the
display device according to the second embodiment;
[0042] FIG. 24 is a plan view illustrating the operation of the
display device according to the second embodiment;
[0043] FIG. 25A is a timing diagram illustrating an operation of a
display device according to a third embodiment;
[0044] FIG. 25B is a timing diagram illustrating an operation of a
display device according to a third embodiment;
[0045] FIG. 25C is a timing diagram illustrating an operation of a
display device according to a third embodiment;
[0046] FIG. 25D is a timing diagram illustrating an operation of a
display device according to a third embodiment;
[0047] FIG. 25E is a timing diagram illustrating an operation of a
display device according to a third embodiment;
[0048] FIG. 25F is a timing diagram illustrating an operation of a
display device according to a third embodiment;
[0049] FIG. 25G is a timing diagram illustrating an operation of a
display device according to a third embodiment;
[0050] FIG. 25H is a timing diagram illustrating an operation of a
display device according to a third embodiment;
[0051] FIG. 25I is a timing diagram illustrating an operation of a
display device according to a third embodiment;
[0052] FIG. 26A is a timing diagram illustrating the operation of
the display device according to the third embodiment;
[0053] FIG. 26B is a timing diagram illustrating the operation of
the display device according to the third embodiment;
[0054] FIG. 26C is a timing diagram illustrating the operation of
the display device according to the third embodiment;
[0055] FIG. 26D is a timing diagram illustrating the operation of
the display device according to the third embodiment;
[0056] FIG. 26E is a timing diagram illustrating the operation of
the display device according to the third embodiment;
[0057] FIG. 26F is a timing diagram illustrating the operation of
the display device according to the third embodiment;
[0058] FIG. 27 is a circuit diagram illustrating a configuration of
a detection circuit of the display device according to the third
embodiment;
[0059] FIG. 28 is a plan view illustrating a configuration of a
display device according to a fourth embodiment.
[0060] FIG. 29 is a circuit diagram illustrating a principle of
touch detection of the display device according to the fourth
embodiment;
[0061] FIG. 30 is a plan view illustrating a configuration of a
display device according to a modified example of the fourth
embodiment;
[0062] FIG. 31 is a plan view schematically illustrating a
configuration of a display device according to a fifth
embodiment;
[0063] FIG. 32 is a circuit diagram illustrating a configuration of
a selection drive circuit of the display device according to the
fifth embodiment;
[0064] FIG. 33 is a circuit diagram illustrating a configuration of
a selection drive circuit of a display device according to a
modified example of the fifth embodiment;
[0065] FIG. 34 is a schematic plan view illustrating a
configuration of a display device according to a sixth
embodiment;
[0066] FIG. 35 is a circuit diagram illustrating a configuration of
a selective connection circuit of the display device according to
the sixth embodiment;
[0067] FIG. 36 is a block diagram illustrating a configuration of a
display device that has been studied by the present inventors;
[0068] FIG. 37 is a block diagram illustrating a configuration of
the display device that has been studied by the present
inventors;
[0069] FIG. 38 is a plan view illustrating a configuration of a
display device according to a modified example of the fourth
embodiment;
[0070] FIG. 39 is a plan view illustrating a configuration of a
display device according to a modified example of the fourth
embodiment; and
[0071] FIG. 40 is a plan view illustrating a configuration of a
display device according to a modified example of the fourth
embodiment.
DESCRIPTIONS OF THE PREFERRED EMBODIMENTS
[0072] Hereinafter, each embodiment of the present invention will
be described with reference to the drawings. Incidentally, the
disclosure is mere an example, and a matter that those skilled in
the art easily think up about appropriate alternations while
keeping a gist of the invention is off course included with the
present invention. In addition, there are cases in which a width, a
thickness, a shape and the like of each portion of the drawings are
schematically illustrated as compared to actual aspects in order
for more clear description, but the drawings are mere examples, and
do not limit the interpretation of the present invention.
[0073] In addition, the same reference numerals are applied to the
same elements that have been described in relation to the foregoing
drawings in the present specification and the respective drawings,
and detailed descriptions thereof will be appropriately omitted in
some cases.
[0074] The following description is given by exemplifying a touch
detection function-equipped liquid crystal display device as a
touch detection function-equipped display device. However, the
invention is not limited thereto, and can be applied also to a
touch detection function-equipped OLED display device. In addition,
although the description has been given by exemplifying two types
of an electromagnetic induction system, a case of employing the
latter system will be described hereinafter. In the latter system,
a battery is not necessarily mounted in a pen, and so it is
possible to reduce a size of the pen and/or to improve a degree of
freedom in shape.
[0075] The electromagnetic induction system includes a system in
which: a coil and a battery are mounted to a pen; a magnetic field
is generated by the pen; and magnetic field energy is detected by a
touch panel. In this case, the touch panel needs to include a
sensor plate that receives the magnetic field energy. Further,
there is another system in which: a coil and a capacitor are
mounted in a pen; a magnetic field is generated by a touch panel;
magnetic field energy is stored in the capacitor mounted in the
pen; and then is detected by the touch panel. In the case of this
system, the magnetic field is generated by the touch panel, and a
sensor plate to receive the magnetic field energy from the pen is
required.
[0076] It is necessary to add the sensor plate receiving
electromagnetic energy in order to realize the touch detection
function-equipped display device in any of the electromagnetic
induction systems, which leads to an increase of price (production
cost).
[0077] In addition, required is a sensor plate for detection of a
change in capacitance even in the capacitance system that detects
the touch by the finger. Thus, it is necessary to add the sensor
plate in order to realize the touch detection function-equipped
display device, which leads to an increase of price.
[0078] In order to enable detection of both the touch by the pen
and the touch by the finger, it is necessary to add the respective
sensor plates, which lead to a further increase of price. For
example, it is conceivable to suppress the increase of price by
utilizing a part of the sensor plate used in the electromagnetic
induction system also as a part of the sensor plate used in the
capacitance system. However, it is required to perform control for
switching the commonly utilized part in the case of the common
utilization, and such control is complicated. In addition, a
control circuit for the control is increased, which restricts the
suppression of the increase of price.
[0079] An object of the present invention is to provide a touch
detection function-equipped display device that can be manufactured
while suppressing an increase of price.
[0080] A display device according to an aspect of the present
invention includes: a pixel array which includes a plurality of
pixels arranged in a matrix form; a plurality of drive wirings each
of which is arranged to extend in a first direction in the pixel
array; and a plurality of detection wirings which are arranged to
extend in a second direction intersecting the first direction in
the pixel array. Here, a periodically changing magnetic field drive
signal is supplied to a first area in a first drive wiring among
the plurality of drive wirings, and a reference signal is supplied
to a second area extending in the first direction with respect to
the first area at a time of detecting an external proximity object.
Accordingly, a magnetic field is generated around the first drive
wiring depending on the magnetic field drive signal. A magnetic
field generated by the external proximity object is changed
depending on whether the external proximity object is proximate to
the first drive wiring. This magnetic field generated by the
external proximity object is detected by the plurality of detection
wirings.
[0081] For example, a configuration where two drive wirings each
extending in the first direction are electrically connected to form
a coil is considered in order to generate the magnetic field. In
this case, connecting control is required between the two drive
wirings. In regard to this, the connecting control is not required
between the drive wirings, and the control becomes easy in the
display device according to an aspect. In addition, it is possible
to suppress an increase of a control circuit(s). As a result, it is
possible to suppress an increase of price of the touch detection
function-equipped display device.
[0082] Also, in the display device according to an aspect of the
present invention, the above-described plurality of drive wirings
include a second drive wiring, the second drive wiring being
arranged to be proximate to the first drive wiring and having a
first area proximate to the first area, and a second area proximate
to the second area. Here, the reference signal is supplied to the
first area of the second drive wiring, and the magnetic field drive
signal is supplied to the second area of the second drive wiring at
the time of detecting the external proximity object. In this case,
the magnetic field generated around the first drive wiring and a
magnetic field generated around the second drive wiring are
superimposed on each other in an area between the first and second
drive wirings. Accordingly, it is possible to strengthen the
magnetic field thus generated.
[0083] Further, a display device according to an aspect of the
present invention is a display device that, in a display area with
first and second sides opposing each other, has a plurality of
drive wirings arranged between the first and second sides and
parallel to each other. The display device includes a first drive
circuit connected to one end portion of each of the plurality of
drive wirings, and a second drive circuit connected to the other
end portion of each of the plurality of drive wirings. Here, the
first drive circuit supplies a magnetic field drive signal to one
end portion of a first drive wiring arranged to be proximate to the
first side, and the second drive circuit supplies a reference
signal to the other end portion of the first drive wiring. At this
time, the first drive circuit supplies the reference signal to one
end portion of a second drive wiring which is arranged to be closer
to the second side than the first drive wiring and to sandwich a
third drive wiring with the first drive wiring, and the second
drive circuit supplies the magnetic field drive signal to the other
end portion of the second drive wiring.
[0084] A strong magnetic field is generated between the first and
second drive wirings, and is applied to the external proximity
object by supplying the magnetic field drive signal and the
reference signal to the first and second drive wirings.
[0085] The first and second drive circuits detect the external
proximity object proximate to the display area during a display
period for one frame in the display area by supplying the magnetic
field drive signal and the reference signal to the drive wirings
selected among the plurality of drive wirings so that drive wirings
respectively corresponding to the first and second drive wirings
are moved from the first side to the second side.
[0086] Accordingly, it is possible to detect the external proximity
object proximate to the display area while preventing the control
from being complicated.
First Embodiment
[0087] A touch detection function-equipped liquid crystal display
device (hereinafter, simply referred to also as a display device)
according to a first embodiment has both functions of touch
detection by an electromagnetic induction system and touch
detection by a capacitance system. That is, it is possible to
perform the detection of touch by the pen and the detection of
touch by the finger. First, each principle of the electromagnetic
induction system and the capacitance system will be described.
<Basic Principle of Electromagnetic Induction System>
[0088] FIG. 1 is an explanatory diagram schematically illustrating
a relationship between an electronic device including the display
device and the pen. In addition, FIGS. 2A to 3B are explanatory
diagrams schematically illustrating the basic principle of the
electromagnetic induction system.
[0089] In FIG. 1, the electronic device includes a display device 1
housed in a metal cover, a light guide plate, a sensor plate, and a
magnetic sheet. The sensor plate is mounted between the display
device 1 and the metal cover in the example illustrated in FIG. 1.
Although a plurality of coils are provided in the sensor plate,
FIG. 1 schematically illustrates one coil among the plurality of
coils as a sensor plate-in coil (hereinafter, simply referred to
also as a coil) L2.
[0090] Further, a coil and a capacitive element are built in a pen
that corresponds to an external proximity object. FIG. 1 does not
illustrate the capacitive element while schematically illustrating
the coil built in the pen as a pen-in coil (hereinafter, simply
referred to also as a coil) L1. The coil L1 and the coil L2 are
coupled by a magnetic field.
[0091] Incidentally, a TFT glass substrate, a color filter and a CF
glass substrate, which are included in the display device 1, are
drawn in FIG. 1 in order to schematically illustrate a structure of
the display device 1. A plurality of layers are formed on the TFT
glass substrate although not illustrated. The color filter is
formed on the CF glass substrate, and a liquid crystal layer not
shown in Figure is sandwiched between the color filter and the TFT
glass substrate. In addition, the light guide plate is fixed by a
fixing part to be sandwiched between the display device 1 and the
sensor plate.
[0092] When the pen is proximate to (including contact) the
electronic device, the coil L1 is proximate to the coil L2.
Accordingly, the magnetic field coupling between the coil L1 and
the coil L2 is generated, and the proximity of the pen is
detected.
[0093] Such detection will be described with reference to FIGS. 2A
to 3B. FIG. 2A illustrates a state in which the coil L2 generates a
magnetic field, and FIG. 2B illustrates a state in which the coil
L1 generates a magnetic field.
[0094] In FIGS. 2A and 2B, the coil L1 inside the pen and a pen-in
capacitive element (hereinafter, also referred to simply as a
capacitive element) C are connected in parallel, thereby forming a
resonant circuit. A coil of single-turn winding is illustrated as
an example of the sensor plate-in coil L2, and has a pair of
terminals. At a time of detecting touch by the pen (during touch
detection), one terminal PT of the coil L2 is connected to output
of a transmission amplifier AP1 for a predetermined time and, after
elapse of the predetermined time, is connected to input of a
reception amplifier AP2 for a predetermined time. Further, the
other terminal of the sensor plate-in coil L2 is connected to a
ground voltage Vss during the touch detection.
[0095] FIGS. 3A and 3B are waveform diagrams illustrating an
operation during the touch detection. A horizontal axis represents
time in FIGS. 3A and 3B, FIG. 3A illustrates a waveform of output
of the transmission amplifier AP1, and FIG. 3B illustrates a
waveform of output of the reception amplifier AP2.
[0096] When the one terminal PT of the coil L2 is connected to the
output of the transmission amplifier AP1, a transmission signal IN
which periodically changes is supplied to the input of the
transmission amplifier AP1. Accordingly, the transmission amplifier
AP1 supplies a periodically changing drive signal .PHI.1 to the one
terminal of the coil L2 for a predetermined time (magnetic field
generation period) TGT depending on a change of the transmission
signal IN as illustrated in FIG. 3A. Accordingly, the coil L2
generates a magnetic field. Magnetic lines at this time are
indicated by .PHI.G in FIG. 2A.
[0097] Since the magnetic lines .PHI.G are generated around a
winding of the coil L2, the magnetic field at an inner side of the
coil L2 becomes strong. When the coil L1 is proximate to the coil
L2 and, for example, a central axis LO of the coil L1 is present at
the inner side of the coil L2 as illustrated in FIG. 2A, the
magnetic lines of the coil L2 reach the coil L1. That is, the coil
L1 is arranged inside the magnetic field generated by the coil L2,
and the coil L1 and the coil L2 are magnetically coupled. The coil
L2 generates the magnetic field, which periodically changes,
depending on the change of the drive signal .PHI.1. Thus, an
induced voltage is generated in the coil L1 according to action of
mutual induction between the coil L2 and the coil L1. The
capacitive element C is charged by the induced voltage generated by
the coil L1.
[0098] After the predetermined time, the one terminal PT of the
coil L2 is connected to input of the reception amplifier AP2 for a
predetermined time (a magnetic field detection period or a current
detection period) TDT. If the capacitive element C is charged in
the previous magnetic field generation period TGT, the coil L1
generates a magnetic field using electric charges charged in the
capacitive element C in the magnetic field detection period TDT.
Magnetic lines of the coil L1 generated by the electric charges
charged in the capacitive element C are indicated by .PHI.D in FIG.
2B.
[0099] If the pen-in coil L1 is proximate to the sensor plate-in
coil L2 during the touch detection, that is, during the magnetic
field generation period TGT and the magnetic field detection period
TDT, the charging of the capacitive element C is performed in the
magnetic field generation period TGT, and the magnetic lines .PHI.D
of the coil L1 reach the coil L2 in the magnetic field detection
period TDT. Since the resonant circuit is configured by the coil L1
and the capacitive element C, the magnetic field generated by the
coil L1 is changed depending on a time constant of the resonant
circuit. As the magnetic field generated by the coil L1 is changed,
an induced voltage is generated in the coil L2. A signal is changed
in the one terminal PT of the coil L2 due to the induced voltage.
This change of the signal is inputted to the reception amplifier
AP2 as a detection signal .PHI.2, is amplified, and outputted from
the reception amplifier AP2 as a sensor signal OUT in the magnetic
field detection period TDT.
[0100] Meanwhile, if the pen-in coil L1 is not proximate to the
sensor plate-in coil L2 during the touch detection, the capacitive
element C is not charged or a charge amount to be charged decreases
in the magnetic field generation period TGT. As a result, the
magnetic lines .PHI.D of the magnetic field generated by the coil
L1 do not reach the coil L2 in the magnetic field detection period
TDT. Thus, the detection signal .phi.2 in the one terminal PT of
the coil L2 is not changed in the magnetic field detection period
TDT.
[0101] FIGS. 3A and 3B illustrate both states when the pen-in coil
L1 is proximate to and is not proximate to the sensor plate-in coil
L2. That is, a state when the coil L1 is not proximate to the coil
L2 is illustrated in a left side in FIGS. 3A and 3B, and a state
when the coil L1 is proximate to the coil L2 is illustrated in a
right side. Thus, the detection signal .PHI.2 is not changed in the
magnetic field detection period TDT illustrated in the left side in
FIG. 3B, and the detection signal .PHI.2 is changed in the magnetic
field detection period TDT illustrated in the right side. It is
possible to detect the touch by the pen by determining pen presence
in a case where the detection signal .PHI.2 is changed, and pen
absence in a case where the detection signal .PHI.2 is not
changed.
[0102] FIGS. 3A and 3B illustrate the determination on the pen
presence and the pen absence, and it is also possible to determine
a distance between the pen and the sensor plate or determine
writing pressure of the pen since a value of the detection signal
.PHI.2 is changed depending on a distance between the coil L1 and
the coil L2.
<Basic Principle of Capacitive System>
[0103] Next, the basic principle of the capacitive system will be
described. Here, a description will be given by exemplifying a case
of detecting touch by the finger using a signal wiring formed in
the display device 1 illustrated in FIG. 1. That is, the
description will be given regarding a case where the sensor plate
of the capacitance system is integrated with the display device.
First, the configuration of the display device 1 illustrated in
FIG. 1 will be described in more detail. FIGS. 4A and 4B are
diagrams schematically illustrating the configuration of the
display device 1. Here, FIG. 4A is a plan view schematically
illustrating a plane of the display device 1, and FIG. 4B is a
cross-sectional view schematically illustrating a cross section of
the display device 1.
[0104] In FIG. 4A, TL(0) to TL(p) represent drive electrodes which
are configured using layers formed on a first main surface TSF1 of
a TFT glass substrate TGB (first substrate). In addition, RL(0) to
RL(p) represent detection electrodes which are configured using
layers formed on a first main surface CSF1 of a CF glass substrate
CGB (second substrate). The TFT glass substrate TGB is provided
with the first main surface TSF1 and a second main surface TSF2
(FIG. 4B) which opposes the first main surface TSF1. Although a
plurality of layers are formed on the first main surface TSF1 of
the TFT glass substrate TGB, FIGS. 4A and 4B illustrate only the
layers forming the drive electrodes TL(0) to TL(p).
[0105] Similarly, the CF glass substrate CGB is provided with the
first main surface CSF1 and a second main surface CSF2 (FIG. 4B)
which opposes the first main surface CSF1. FIGS. 4A and 4B
illustrate only the layers forming the detection electrodes RL(0)
to RL(p) arranged on the first main surface CSF1. FIG. 4A
illustrates the TFT glass substrate TGB and the CF glass substrate
CGB which are isolated from each other to facilitate the
understanding. Specifically, the first main surface TSF1 of the TFT
glass substrate TGB (first substrate) and the second main surface
CSF2 of the CF glass substrate CGB (second substrate) are arranged
to oppose each other with the liquid crystal layer sandwiched
therebetween as illustrated in FIG. 4B.
[0106] Although the plurality of layers, the liquid crystal layer,
and the like are sandwiched between the first main surface TSF1 of
the TFT glass substrate TGB and the second main surface CSF2 of the
CF glass substrate CGB, FIGS. 4A and 4B illustrate only the drive
electrodes TL(0) to TL(n+2), the liquid crystal layer and the color
filter which are sandwiched between the first main surface TSF1 and
the second main surface CSF2. In addition, the plurality of
detection electrodes RL(0) to RL(p) and a polarizing plate are
arranged on the first main surface CSF1 of the CF glass substrate
CGB as illustrated in FIG. 4A. FIG. 4B illustrates only a detection
electrode RL(n) among the plurality of detection electrodes RL(0)
to RL(p) as an example of the detection electrode.
[0107] In the present specification, the description is given a
state when the display device 1 is viewed as a plain view from the
first main surfaces CSF1 and TSF1 of the CF glass substrate CGB and
the TFT glass substrate TGB side as illustrated in FIG. 4B. That
is, the plan view is the state that is viewed from sides of the
first main surfaces CSF1 and TSF1 of the CF glass substrate CGB and
the TFT glass substrate TGB. Thus, it has been described that the
detection electrode and the polarizing plate are arranged on the
first main surface CSF1 of the CF glass substrate CGB side. But,
the detection electrode and the polarizing plate are arranged on
right, left or lower side of the CF glass substrate CGB, for
example, when a direction of the viewing is changed. In FIG. 4B,
numeral 13 represents an amplifier circuit which is connected to
the detection electrode RL(n).
[0108] When seen in the plan view from the first main surface CSF1
and TSF1 sides, the drive electrodes TL(0) to TL(p) extend in a row
direction (horizontal direction) and are arranged in parallel in a
column direction (vertical direction) on the first main surface
TSF1 of the TFT glass substrate TGB as illustrated in FIG. 4A. In
addition, the detection electrodes RL(0) to RL(p) extend in the
column direction (vertical direction) and are arranged in parallel
the row direction (horizontal direction) on the first main surface
CSF1 of the CF glass substrate CGB as illustrated in FIG. 4A.
[0109] As illustrated in FIG. 4B, the CF glass substrate CGB, the
liquid crystal layer, and the like are sandwiched between the drive
electrodes TL(0) to TL(p) and the detection electrodes RL(0) to
RL(p). Thus, the drive electrodes TL(0) to TL(p) and the detection
electrodes RL(0) to RL(p) cross each other when seen in the plan
view, but are electrically isolated from each other. Since
capacitance is present between the drive electrode and the
detection electrode, this capacitance is illustrated in broken
lines as a capacitive element in FIG. 4B. Incidentally, the drive
electrodes TL(0) to TL(p) are isolated from each other, and the
detection electrodes RL(0) to RL(p) are also isolated from each
other.
[0110] A drive signal for display (display drive signal) is
supplied to the drive electrodes TL(0) to TL(p) at a time of
display, and a drive signal for touch detection is supplied thereto
at a time of detecting the touch by the finger.
[0111] In the first embodiment, the detection of touch by the
finger is performed using the electric field, and the detection of
touch by the pen is performed using the magnetic field (see FIG. 1,
FIGS. 2A and 2B, and FIGS. 3A and 3B). Thus, the detection of touch
using the magnetic field will be referred to as magnetic field
touch detection, and the detection of touch using the electric
field will be referred to as electric field touch detection in the
present specification. Although will be described later, the drive
signal for touch detection is supplied to the drive electrodes
TL(0) to TL(p) even at the time of magnetic field touch detection.
Thus, a drive signal which corresponds to each of the display, the
electric field touch detection, and the magnetic field touch
detection is supplied to the drive electrodes TL(0) to TL(p) at
each time of the display, the electric field touch detection, and
the magnetic field touch detection. That is, the drive electrodes
TL(0) to TL(p) are commonly used (shared) among the time of
display, the time of electric field touch detection, and the time
of magnetic field touch detection. Each of the drive electrodes
TL(0) to TL(p) can be regarded as a common electrode when seen from
the viewpoint of being commonly used.
[0112] A drive signal Tx for an electric field is supplied to the
drive electrodes TL(0) to TL(p) in a period for the electric field
touch detection. A signal whose voltage periodically changes is
supplied as the drive signal Tx to the drive electrode selected so
as to detect the touch, and a predetermined fixed voltage, for
example, is supplied as the drive signal Tx to the drive electrode
which is not selected so as not to detect the touch. The drive
electrodes TL(0) to TL(p) are sequentially selected in this order,
for example, in the electric field touch detection period. Although
FIG. 4A illustrates a state in which the signal with the
periodically changing voltage is supplied to the drive electrode
TL(2) as a drive signal Tx(2), the drive electrodes are
sequentially selected, for example, from the drive electrode TL(0)
to TL(p), and the drive signal with the periodically changing
voltage is supplied thereto.
[0113] On the other hand, the predetermined fixed voltage or a
voltage in accordance with image information to be displayed is
supplied to the drive electrodes TL(0) to TL(p) as the display
drive signal in a period for the display.
[0114] Next, a basic principle of the capacitive system will be
described with reference to FIGS. 5A to 5C. In FIGS. 5A to 5C,
reference signs TL(0) to TL(p) indicate the drive electrodes
illustrated in FIGS. 4A and 4B, and reference signs RL(0) to RL(p)
indicate the detection electrodes illustrated in FIGS. 4A and 4B.
In FIG. 5A, the respective drive electrodes TL(0) to TL(p) extend
in the row direction and are arranged in parallel in the column
direction. Further, the respective detection electrodes RL(0) to
RL(p) extend in the column direction and are arranged in parallel
in the row direction so as to cross the drive electrodes TL(0) to
TL(p). The liquid crystal layer and the like is arranged between
the detection electrodes RL(0) to RL(p) and the drive electrodes
TL(0) to TL(p) so that a gap is formed between the detection
electrodes RL(0) to RL(p) and the drive electrodes TL(0) to TL(p)
as illustrated in FIG. 4B.
[0115] In FIG. 5A, each of numerals 12-0 to 12-p schematically
illustrates a unit drive electrode driver. In FIG. 5A, the drive
signals Tx(0) to Tx(p) are outputted from the unit drive electrode
driver 12-0 to 12-p. Further, each of numerals 13-0 to 13-p
schematically illustrates a unit amplification circuit. In FIG. 5A,
a pulse signal surrounded by .smallcircle. (circle) of a solid line
indicates a waveform of the drive signal Tx to be supplied to the
selected drive electrode. The finger is represented by numeral FG
as an external proximity object in FIG. 5A.
[0116] The pulse signal is supplied from the unit drive electrode
driver 12-2 to the drive electrode TL(2) as the drive signal Tx(2)
in the example of FIG. 5A. When the drive signal Tx(2), which is
the pulse signal, is supplied to the drive electrode TL(2), an
electric field is generated between the drive electrode TL(2) and
the crossing detection electrode RL(n) as illustrated in FIG. 5B.
At this time, when the finger FG touches a position proximate to
the drive electrode TL(2) of the liquid crystal panel, an electric
field is also generated between the finger FG and the drive
electrode TL(2), and the electric field generated between the drive
electrode TL(2) and the detection electrode RL(n) is reduced.
Accordingly, an electric charge amount between the drive electrode
TL(2) and the detection electrode RL(n) is reduced. As a result,
the electric charge amount generated in response to the supply of
the drive signal Tx(2) is reduced by .DELTA.Q at the time of the
touch of the finger FG as compared to the time of the non-touch
thereof as illustrated in FIG. 5C. A difference in electric charge
amount is represented as a difference in voltage in the detection
signal Rx(n), and is supplied to the unit amplification circuit
13-n and amplified.
[0117] Incidentally, a horizontal axis represents time, and a
vertical axis represents the electric charge amount in FIG. 5C. The
electric charge amount increases (increases in an upper side in
FIG. 5C) in response to a rise in voltage of the drive signal
Tx(2), and the electric charge amount increases (increases in a
lower side in FIG. 5C) in response to a drop in voltage of the
drive signal Tx(2). At this time, an increasing amount of electric
charges is changed depending on absence or presence of the touch of
the finger FG Further, reset is performed before the electric
charge amount increases toward the lower side from after increasing
toward the upper side, and reset is performed similarly before the
electric charge amount increases toward the upper side from after
increasing toward the lower side in FIG. 5C. In this manner, the
electric charge amount is vertically changed with the reset
electric charge amount as a reference. In other words, a signal
change is generated in the detection electrode RL(n) in response to
the touch.
[0118] When the drive electrodes TL(0) to TL(p) are sequentially
selected and the drive signals Tx(0) to Tx(p) which are the pulse
signals are supplied to the selected drive electrode, the detection
signals Rx(0) to Rx(p), each of which has a voltage value in
response to whether the finger FG touches the position proximate to
each crossing portion between the selected drive electrode and the
crossing plurality of detection electrodes RL(0) to RL(p), are
outputted from each of the plurality of detection electrodes RL(0)
to RL(p) crossing with the selected drive electrode. Each of the
detection signals Rx(0) to Rx(p) is sampled, and is converted into
a digital signal using an analog/digital conversion unit at a time
at which a gap .DELTA.Q is generated in the electric charge amount.
A coordinate of the touched position can be extracted by performing
a signal processing of the converted digital signal.
<Integrated Structure of Display Device and Sensor Plate-in
Coil>
[0119] The present inventors have considered that an electronic
device becomes costly in a case of separately preparing the display
device 1 and the sensor plate as illustrated in FIG. 1 because the
sensor plate is costly. Thus, the inventors have considered to form
the coil L2 (FIG. 1) configuring the sensor plate using a layer of
the display device 1, and to integrate the display device and the
sensor plate.
[0120] FIGS. 6A and 6B are cross-sectional views illustrating
schematic cross sections of the display device 1 with which the
sensor plate is integrated as a sensor layer (layer). FIGS. 6A and
6B are similar to FIG. 1, and thus, a different point will mainly
be described. In FIG. 1, the sensor plate is prepared separately
from the display device 1, and the sensor plate is provided between
the light guide plate and the magnetic sheet. On the contrary, the
sensor layer is formed on the CF glass substrate CGB in FIG. 6A. In
addition, the sensor layer is formed on the TFT glass substrate TGB
in FIG. 6B. Accordingly, the sensor layer corresponding to the
sensor plate is provided in the display device 1, and thus it is
possible to suppress the increase of price.
[0121] As described in FIGS. 2A to 3B, the sensor plate-in coil L2
generates the magnetic field in the magnetic field generation
period TGT, and the magnetic field generated by the pen-in coil L1
is detected by the sensor plate-in coil L2 in the magnetic field
detection period TDT. That is, the sensor plate-in coil L2 is
commonly used for generation of the magnetic field and detection of
the magnetic field. In the case of being commonly used in this
manner, the coil L2 is configured by the layer formed on the CF
glass substrate CGB in FIG. 6A. Similarly, the coil L2 is
configured by the layer formed on the TFT glass substrate TGB in
FIG. 6B.
[0122] However, it is also possible to separately form the coil
that generates the magnetic field in the magnetic field generation
period TGT, and the coil that detects the magnetic field in the
magnetic field detection period TDT. In this case, for example, the
coil to generate the magnetic field (hereinafter, referred to also
as a magnetic field generation coil) can be formed using the sensor
layer illustrated in FIG. 6B, and the coil to detect the magnetic
field (hereinafter, referred to also as a magnetic field detection
coil) can be formed using the sensor layer illustrated in FIG. 6A.
In addition, there are a plurality of layers that can be used as
the sensor layer on the TFT glass substrate TGB. Thus, it is also
possible to separately form the magnetic field generation coil and
the magnetic field detection coil using the sensor layers
illustrated in FIG. 6B.
[0123] FIG. 7 illustrates an example of the case of separately
forming the magnetic field generation coil and the magnetic field
detection coil. FIG. 7 illustrates the case where the magnetic
field generation coil and the magnetic field detection coil are
configured using the layers formed on the TFT glass substrate TGB.
In FIG. 7, for example, CX(n) to CX(n+2) represent the magnetic
field generation coils and CY(n) to CY(n+2) represent the magnetic
field detection coils. In FIG. 7, the drive electrodes TL(0) to
TL(p) described in FIGS. 4A and 4B are used as the layers forming
the magnetic field generation coils, and signal lines SL(0) to
SL(p) to transmit image information are used as the layers forming
the magnetic field detection coil. Although will be described
later, the signal lines SL(0) to SL(p) are configured using the
layers formed on the TFT glass substrate TGB, similarly to the
drive electrodes TL(0) to TL(p), extend in the horizontal direction
and are arranged in parallel in the vertical direction in FIG.
7.
[0124] As illustrated in FIGS. 4A, 4B and 7, the drive electrodes
TL(0) to TL(p) extend in the horizontal direction to be parallel to
each other. As illustrated in FIG. 7, one end portion of each of
the drive electrodes TL(n+1) and TL(n+2) and one end portion of
each of the drive electrodes TL(n+6) and TL(n+7) are electrically
connected, and the other end portion of each of the drive
electrodes TL(n) to TL(n+2) and the other end portion of each of
the drive electrodes TL(n+6) to TL(n+8) are electrically connected
in the magnetic field generation period TGT. Accordingly, a coil
CX(n) with a three-turn winding is formed as a winding by using the
drive electrodes TL(n) to TL(n+2) and TL(n+6) to TL(n+8). In the
same manner, it is possible to form three-turn-winding coils
CX(n+1), CX(n+2) and so on by electrically connecting predetermined
drive electrodes in the magnetic field generation period TGT.
[0125] Similarly, one end portion of each of the signal lines
SL(n+1) and SL(n+2) and one end portion of each of the signal lines
SL(n+6) and SL(n+7) are electrically connected, and the other end
portion of each of the signal lines SL(n) to SL(n+2) and the other
end portion of each of the signal lines SL(n+6) to SL(n+8) are
electrically connected in the magnetic field detection period TDT.
Accordingly, a coil CY(n) with a three-turn winding is formed as a
winding by using the signal lines SL(n) to SL(n+2) and SL(n+6) to
SL(n+8). In the same manner, it is possible to form
three-turn-winding coils CY(n+1), CY(n+2) and so on by electrically
connecting predetermined signal lines in the magnetic field
detection period TDT.
[0126] The coils CX(n) to CX(n+2) and the coils CY(n) to CY(n+2)
cross each other in electrically isolated states. For example, one
end portion of the drive electrode TL(n) forming the coil CX(n)
corresponds to the terminal PT illustrated in FIGS. 2A and 2B, and
the output from the transmission amplifier AP1 illustrated in FIG.
1 is supplied thereto and the ground voltage Vss is supplied to the
other end portion of the drive electrode TL(n+8) in the magnetic
field generation period TGT. Accordingly, the magnetic field is
generated in the coil CX(n) as described in FIG. 2A. Electric
charges are stored in the capacitive element C (FIGS. 2A and 2B)
inside the pen by the magnetic field generated in the coil
CX(n).
[0127] In the magnetic field detection period TDT, predetermined
signal lines are electrically connected, and the coils CY(n) to
CY(n+2) are formed. The coil L1 (FIG. 1) generates the magnetic
field using the electric charges stored in the capacitive element C
inside the pen. The magnetic field generated at this time is
detected by the coils CY(n) to CY(n+2). Accordingly, it is possible
to detect the proximity of the pen or a distance between the pen
and an area in close proximity thereto.
<Problem of Magnetic Field Generation Coil>
[0128] The present inventors have studied a configuration of a
display device in a case of using a magnetic field generation coil
in an electromagnetic induction system prior to the present
invention. FIGS. 36 and 37 are block diagrams illustrating the
configuration of the display device that has been previously
studied by the present inventors. Here, the case of using a drive
electrode as the magnetic field generation coil will be described
as similar to FIG. 7.
[0129] In FIGS. 36 and 37, TL(n) to TL(n+5) represent the drive
electrodes. In addition, each of USR(n) to USR(n+5) and USL(n) to
USL(n+5) represents a unit drive circuit. In FIGS. 36 and 37, VCOM
represents a voltage wiring that supplies the ground voltage Vss;
TSV represents a signal wiring that supplies a drive signal TSVCOM
with a periodically changing voltage; and CNR and CNL represent
signal wirings which connect the drive electrodes to each other in
the magnetic field generation period TGT.
[0130] In FIGS. 36 and 37, SL11 to SL13, SL21 to SL23, SL31 to
SL33, SL41 to SL43, and SL51 to SL53 and SL61 to SL63 represent
switches. The switches SL11 to SL13 are provided as a set of a
first switch group and correspond to the drive electrode TL(n).
Similarly, the switches SL21 to SL23 are provided as a set of the
first switch group and correspond to the drive electrode TL(n+1);
the switches SL31 to SL33 are provided as a set of the first switch
group and correspond to the drive electrode TL(n+2); and the
switches SL41 to SL43 are provided as a set of the first switch
group and correspond to the drive electrode TL(n+3). In addition,
the switches SL51 to SL53 are provided as a set of the first switch
group and correspond to the drive electrode TL(n+4); and the
switches SL61 to SL63 are provided as a set of the first switch
group and correspond to the drive electrode TL(n+5).
[0131] The switches SL11, SL21, SL31, SL41, SL51 and SL61 among the
switches forming the respective first switch groups are used as
first switches, and each of the first switches is connected to the
signal wiring TSV and one end portion of the corresponding drive
electrode. In addition, the switches SL12, SL22, SL32, SL42, SL52
and SL62 among the switches forming the first switch groups are
used as second switches, and each of the second switches is
connected to the voltage wiring VCOM and one end portion of the
corresponding drive electrode. Further, the switches SL13, SL23,
SL33, SL43, SL53 and SL63 among the switches forming the first
switch groups are used as third switches, and each of the third
switches is connected to the signal wiring CNL and one end portion
of the corresponding drive electrode.
[0132] In FIGS. 36 and 37, SR11 to SR13, SR21 to SR23, SR31 to
SR33, SR41 to SR43, SR51 to SR53 and SR61 to SR63 also represent
switches. The switches SR11 to SR13 are provided as a set of a
second switch group and correspond to the drive electrode TL(n).
Similarly, the switches SR21 to SR23 are provided as a set of the
second switch group and correspond to the drive electrode TL(n+1);
the switches SR31 to SR33 are provided as a set of the second
switch group and correspond to the drive electrode TL(n+2); and the
switches SR41 to SR43 are provided as a set of the second switch
group and correspond to the drive electrode TL(n+3). In addition,
the switches SR51 to SR53 are provided as a set of the second
switch group and correspond to the drive electrode TL(n+4); and the
switches SR61 to SR63 are provided as a set of the second switch
group and correspond to the drive electrode TL(n+5).
[0133] Here, the switches SR11, SR21, SR31, SR41, SR51 and SR61
among the switches forming the respective second switch groups are
used also as first switches, and each of the first switches is
connected to the signal wiring TSV and the other end portion of the
corresponding drive electrode. In addition, the switches SR12,
SR22, SR32, SR42, SR52 and SR62 among the switches forming the
second switch groups are used as second switches, and each of the
second switches is connected to the voltage wiring VCOM and the
other end portion of the corresponding drive electrode. Further,
the switches SR13, SR23, SR33, SR43, SR53 and SR63 among the
switches forming the second switch groups are used as third
switches, and each of the third switches is connected to the signal
wiring CNL and the one end portion of the corresponding drive
electrode.
[0134] Each of the unit drive circuits USL(n) to USL(n+5)
corresponds to each of the drive electrodes TL(n) to TL(n+5), and
each of the unit drive circuits USR(n) to USR(n+5) also corresponds
to each of the drive electrodes TL(n) to TL(n+5). Each of the unit
drive circuits USL(n) to USL(n+5) and USR(n) to USR(n+5) controls
the first switch group and the second switch group so that the
magnetic field and the electric field are generated around the
corresponding drive electrode at each time of magnetic field touch
detection and electric field touch detection.
[0135] That is, in the case of generating the magnetic field in the
corresponding drive electrode, the first switch group and the
second switch group are controlled so that two drive electrodes,
which are arranged with the corresponding drive electrode
sandwiched therebetween, are selected. The coil is configured using
the two selected drive electrodes, and the corresponding drive
electrode is arranged at an inner side of the coil. Accordingly,
the strong magnetic field is generated in the area of the
corresponding drive electrode. On the other hand, in the case of
generating the electric field around the corresponding drive
electrode, the first switch group and the second switch group are
controlled so that the corresponding drive electrode is
selected.
<<Magnetic Field Touch Detection>>
[0136] A description will be given regarding an operation in a case
of generating a magnetic field in an area of the drive electrode
TL(n+2) at the time of magnetic field touch detection as follows.
The drive electrodes TL(n+1) and TL(n+3) are drive electrodes that
sandwich the drive electrode TL(n+2). The unit drive circuits
USL(n+2) and USR(n+2), which correspond to the drive electrode
TL(n+2), control the first switch groups (SL21, SL22, SL23) and
(SL41, SL42, SL43) and the second switch groups (SR21, SR22, SR23)
and (SR41, SR42, SR43). The respective first and second switch
groups correspond to the drive electrodes TL(n+1) and TL(n+3) that
sandwich the drive electrode TL(n+2).
[0137] That is, the unit drive circuit USL(n+2) turns the first
switch SL21 and the second switch SL42 in the first switch groups
(SL21, SL22, SL23) and (SL41, SL42, SL43) into an on-state
(conductive state) and the remaining switches into an off-state
(non-conductive state). In addition, the unit drive circuit
USR(n+2) turns the third switches SR23 and SR43 in the second
switch groups (SR21, SR22, SR23) and (SR41, SR42, SR43) into the
on-state (conductive state) and the remaining switches into the
off-state (non-conductive state).
[0138] Accordingly, one end portion of the drive electrode TL(n+1)
is connected to the signal wiring TSV via the first switch SL21,
and the other end portion of the drive electrode TL(n+1) is
connected to the signal wiring CNR via the third switch SR23 as
illustrated in FIG. 36. In addition, the one end portion of the
drive electrode TL(n+3) is connected to the voltage wiring VCOM via
the second switch SL42, and the other end portion of the drive
electrode TL(n+3) is connected to the signal wiring CNR via the
third switch SR43. As a result, the respective other end portions
of the drive electrodes TL(n+1) and TL(n+3), which are arranged in
parallel to the drive electrode TL(n+2) sandwiched therebetween,
are electrically connected via the signal wiring CNR, thereby
forming the coil having the drive electrode TL(n+2) at the inner
side thereof.
[0139] In the case of the magnetic field touch detection, the
ground voltage Vss is supplied to the voltage wiring VCOM, and the
drive signal TSVCOM with the periodically changing voltage is
supplied to the signal wiring TSV in the magnetic field generation
period TGT. Accordingly, the drive signal TSVCOM is supplied to the
one end portion of the drive electrode TL(n+1) as the magnetic
field drive signal via the first switch SL21, and the ground
voltage Vss is supplied to the one end portion of the drive
electrode TL(n+3) via the second switch SL42. Accordingly, the
magnetic field is generated by the magnetic field generation coil
configured by the drive electrodes TL(n+1) and TL(n+3), and the
strong magnetic field is formed around the drive electrode
TL(n+2).
[0140] In FIG. 36, arrows I1, 12 indicate currents flowing to the
drive electrodes TL(n+1) and TL(n+3) by the drive signal TSVCOM and
directions thereof. When the current I1 flows, the drive electrode
TL(n+1) generates a magnetic field in a direction indicated by a
broken-line arrow .PHI.I1. The direction of the current I2 flowing
to the drive electrode TL(n+3) is exactly opposite to the direction
of the current I1, and thus the drive electrode TL(n+3) generates a
magnetic field in a direction indicated by a broken-line arrow
.PHI.I2. The magnetic field generated by the drive electrode
TL(n+1) and the magnetic field generated by the drive electrode
TL(n+3) are superimposed on each other around the drive electrode
TL(n+2), thereby generating the strong magnetic field.
[0141] Incidentally, the first switch, the second switch, and the
third switch in the first switch group and the second switch group,
except for the first switch groups (SL21, SL22, SL23) and (SL41,
SL42, SL43) and the second switch groups (SR21, SR22, SR23) and
(SR41, SR42, SR43) described above, are turned into the off-state
by the unit drive circuits except for the above-described unit
drive circuits USL(n+2) and USR(n+2).
[0142] The unit drive circuits USL(n) to USL(n+5) are connected in
series and each have a function of operating as a shift register.
Similarly, the unit drive circuits USR(n) to USR(n+5) are also
connected in series and each have a function of operating as the
shift register. Selection information to select the drive electrode
which generates the magnetic field is set to, for example, the unit
drive circuits USL(n) and USR(n), and the selection information is
sequentially shifted toward the unit drive circuits USL(n+5) and
USR(n+5). The unit drive circuits at which the selection
information arrive control the first switch group and the second
switch group as described above, and perform the control so that
the magnetic field is generated around the corresponding drive
electrode. That is, FIG. 36 illustrates a state where the selection
information arrives at the unit drive circuits USL(n+2) and
USR(n+2).
[0143] FIG. 37 illustrates a state where the selection information
arrives at the unit drive circuits USL(n+3) and USR(n+3) by the
shift operation. An operation at the time when the selection
information arrives at the unit drive circuits USL(n+3) and
USR(n+3) is the same as the operation described with reference to
FIG. 36, and thus will not be described.
[0144] In this manner, the drive electrode, which generates the
strong magnetic field, is sequentially changed (moved) as the
selection information is shifted.
<<Electric Field Touch Detection>>
[0145] Next, a description will be given regarding an operation in
a case of electric field touch detection. Here, the description
will be also given by exemplifying the drive electrode TL(n+2).
[0146] In the electric field touch detection, the unit drive
circuits USL(n+2) and USR(n+2) control the first switch group and
the second switch group which are different from those in the case
of the magnetic field touch detection. That is, the first switch
group (SL31, SL32, SL33) and the second switch group (SR31, SR32,
SR33), which are connected to the corresponding drive electrode
TL(n+2) that corresponds to the unit drive circuits USL(n+2) and
USR(n+2), are controlled. In this case, the first switch SL31 in
the first switch group (SL31, SL32, SL33) and the first switch SR31
in the second switch group (SR31, SR32, SR33) are turned into the
on-state, and the second switches SL32 and SR32 and the third
switches SL33 and SR33 are turned into the off-state.
[0147] The drive signal TSVCOM with the periodically changing
voltage is supplied to the signal wiring TSV even in the electric
field touch detection. Thus, the drive signal TSVCOM is supplied to
the drive electrode TL(n+2) as the electric field drive signal from
both end portions thereof via the first switches SL31 and SR31. At
this time, the first switch, the second switch, and the third
switch in the remaining first switch group and second switch group
are turned in the off-state. Thus, the drive electrodes TL(n) to
TL(n+1) and TL(n+3) to TL(n+5) are in a floating state.
[0148] When the selection information is shifted to the unit drive
circuits USL(n+3) and USR(n+3) from the unit drive circuits
USL(n+2) and USR(n+2) by the shift operation, the unit drive
circuits USL(n+3) and USR(n+3) controls the first switch group and
the second switch group, which are connected to the corresponding
drive electrode TL(n+3), in the same manner as above. Accordingly,
the drive signal TSVCOM is supplied to the drive electrode TL(n+3)
as the electric field drive signal.
<<Problem>>
[0149] In the case of the magnetic field touch detection, it is
required for forming the magnetic field generation coil that a
plurality of drive electrodes arranged in parallel to each other
are connected to the signal wiring (CNR or CNL) and the third
switch, as described above. In addition, a switch group, which is
connected to a drive electrode different from a drive electrode
arranged in a generating area of a strong magnetic field, is
controlled in this case. On the contrary, a switch group, which is
connected to a drive electrode arranged in a generating area of an
electric field, is controlled in the case of the electric field
touch detection. Thus, a problem that the control becomes
complicated occurs. Further, there arises a problem of an increase
in the occupied area of the drive circuit (control circuit) that
performs the control.
<Overall Configuration of Display Device>
[0150] FIG. 8 is a block diagram illustrating the configuration of
the display device 1 according to the first embodiment. Here, a
description will be given by exemplifying a case where the display
device 1 is a liquid crystal display device although not
particularly limited thereto. In FIG. 8, the display device 1 is
provided with a display panel (liquid crystal panel) 2, a signal
line selector 3, a display control device 4, a gate driver 5, and a
touch control device 6. In addition, the display device 1 is
provided with selection drive circuits (a first drive circuit and a
second drive circuit) SSR and SSL, a switching regulator circuit
SCX, and an amplifier circuit AMP. These devices and circuits
provided in the display device 1 will be described later in detail,
and so the overall overview will be described here.
[0151] The display panel 2 includes a pixel array LCD in which a
plurality of pixels are arranged in a matrix form although will be
described later with reference to FIG. 12. A plurality of signal
lines, a plurality of drive electrodes, and a plurality of scan
lines are arranged in the pixel array LCD. Here, the signal lines
are arranged in respective columns of the pixel array LCD; the
drive electrodes are arranged in rows of the pixel array LCD; and
the plurality of scan lines are arranged in the respective rows of
the pixel array LCD. When the description is given with reference
to FIG. 8, the signal wirings extend in the vertical direction
(column direction) and are arranged in parallel in the horizontal
direction (row direction). Further, the drive electrodes extend in
the horizontal direction and are arranged in parallel in the
vertical direction. Further, the scan lines extend in the
horizontal direction and are arranged in parallel in the vertical
direction. In this case, the pixel is arranged in a portion at
which the signal line and the scan line cross each other. The pixel
is selected by the signal line and the scan line; a voltage of the
signal line and a voltage (display drive signal) of the drive
electrode at the time are applied to the selected pixel; and the
selected pixel performs display according to a voltage gap between
the signal line and the drive electrode in a period for the display
(display period).
[0152] The display control device 4 is provided with a control
circuit D-CNT and a signal line driver D-DRV. The control circuit
D-CNT receives a timing signal supplied to an external terminal Tt,
and image information supplied to an input terminal Ti; forms an
image signal Sn according to the image information supplied to the
input terminal Ti; and supplies the image signal Sn to the signal
line driver D-DRV. The signal line driver D-DRV supplies the
supplied image signal Sn to the signal line selector 3 in a time
division manner in the display period. Further, the control circuit
D-CNT receives the timing signal supplied to the external terminal
Tt, and a control signal SW sent from the touch control device 6;
and forms various types of control signals. The control signal to
be formed by the control circuit D-CNT includes: selection signals
SEL1 and SEL2 supplied to the signal line selector 3; a
synchronization signal TSHD; a clock signal CLK; a magnetic field
enable signal SC_EN; an electric field enable signal TC_EN; the
drive signal TSVCOM; a control signal Y-CNT relating to the touch
detection; a clock signal CLK; and the like.
[0153] Among the signals to be formed by the control circuit D-CNT,
the magnetic field enable signal SC_EN is an enable signal
indicating implementation of the magnetic field touch detection,
and the electric field enable signal TC-EN is an enable signal
indicating implementation of the electric field touch detection. In
addition, the synchronization signal TSHD is a synchronization
signal which identifies the period (display period), in which the
display is performed in the display panel 2, and the period (touch
detection period), in which the touch detection (the magnetic field
touch detection and the electric field touch detection) is
performed. The drive signal TSVCOM is a signal whose voltage
periodically changes and which is supplied to the drive electrode
as the magnetic field drive signal or the electric field drive
signal in the touch detection period.
[0154] The signal line driver D-DRV supplies the image signal Sn to
the signal line selector 3 in a time division manner according to
the selection signals SEL1 and SEL2 in the display period. The
signal line selector 3 is connected to the plurality of signal
lines arranged in the display panel 2, and supplies the supplied
image signal to a suitable signal line according to the selection
signals SEL1 and SEL2 in the display period. The gate driver 5
forms scan line signals Vs0 to Vsp according to the timing signal
sent from the control circuit D-CNT, and supplies the scan line
signal to a scan line inside the display panel 2 in the display
period. In the display period, a pixel, which is connected to a
scan line to which a high-level scan line signal is supplied, is
selected, and the selected pixel performs display according to the
image signal supplied to the signal line at the time, thereby
performing the display.
[0155] The touch control device 6 is provided with a detection
circuit DET which receives sense signals S(0) to S(p); a processing
circuit PRS which processes a detection signal DET-D sent from the
detection circuit DET to extract a coordinate of a touched
position; and a control circuit T-CNT. The control circuit T-CNT
receives the synchronization signal TSHD, the magnetic field enable
signal SC_EN, and the electric field enable signal TC_EN from the
display control device 4, and performs control so that the touch
control device 6 operates in synchronization with the display
control device 4.
[0156] That is, the control circuit T-CNT performs control so that
the detection circuit DET and the processing circuit PRS operate
when the synchronization signal TSHD, the magnetic field enable
signal SC_EN, and the electric field enable signal TC_EN indicate
the touch detection. In addition, the control circuit T-CNT
receives the detection signal from the detection circuit DET, forms
the control signal SW, and supplies the control signal to the
control circuit D-CNT. The processing circuit PRS outputs the
extracted coordinate from an external terminal To as coordinate
information.
[0157] The display panel 2 has sides 2-U and 2-D, which are
parallel to the row of the pixel array LCD, and sides 2-R and 2-L
which are parallel to the column of the pixel array LCD. Here, the
side 2-U and the side 2-D are sides opposing each other, and are
arranged so that the plurality of drive electrodes and the
plurality of scan lines in the pixel array LCD are sandwiched
between the two sides. In addition, the side 2-R and the side 2-L
are also sides opposing each other and are arranged so that the
plurality of signal lines in the pixel array LCD are sandwiched
between these two sides.
[0158] The selection drive circuit SSR is arranged along the side
2-R of the display panel 2, and the selection drive circuit SSL is
arranged along the side 2-L of the display panel 2. The selection
drive circuit SSR is coupled with the plurality of drive electrodes
arranged on the display panel 2 on the side 2-R of the display
panel 2 side, and the selection drive circuit SSL is coupled with
the plurality of drive electrodes arranged on the display panel 2
on the side 2-L of the display panel 2 side. That is, the selection
drive circuits SSR and SSL are connected to the drive electrode
arranged on the display panel 2 outside the display panel 2.
[0159] The selection drive circuit SSR is provided with a drive
circuit SR-R and a selection circuit SR-C. The drive circuit SR-R
is provided with a shift register having a plurality of shift
stages, and selection information SEI is set to the shift register
by the control signal Y-CNT. The set selection information SEI is
sequentially shifted in synchronization with the clock signal
CLK.
[0160] When the magnetic field touch detection is designated by the
magnetic field enable signal SC_EN, the drive circuit SR-R forms
and outputs a selection signal according to the selection
information stored in the shift register. Although not particularly
limited, the drive circuit SR-R forms two selection signals
according to the selection information when the magnetic field
touch detection is designated in the first embodiment. On the other
hand, when the electric field touch detection is designated by the
electric field enable signal TC_EN, the drive circuit SR-R also
forms and outputs a selection signal according to the selection
information stored in the shift register. Although not particularly
limited, the drive circuit SR-R forms one selection signal
according to the selection information when the electric field
touch detection is designated in the first embodiment.
[0161] The selection circuit SR-C receives the selection signal
from the drive circuit SR-R and connects the drive electrode, which
is designated by the selection signal, to the signal wiring
(magnetic field drive signal wiring) TSV and the voltage wiring
(reference signal wiring) VCOM. That is, the drive electrode, which
is designated by one selection signal from between the two
selection signals, is connected to the signal wiring TSV, and the
drive electrode designated by the other selection signal is
connected to the voltage wiring VCOM at the time of magnetic field
touch detection. On the other hand, the drive electrode designated
by the single selection signal is connected to the signal wiring
TSV at the time of electric field touch detection.
[0162] In the first embodiment, the ground voltage Vss is supplied
to the voltage wiring VCOM at the time of magnetic field touch
detection. In addition, the drive signal TSVCOM with the
periodically changing voltage is supplied to the signal wiring TSV
at each time of magnetic field touch detection and electric field
touch detection. Thus, the drive signal TSVCOM is supplied to the
drive electrode, which is designated by one selection signal from
between the two selection signals, as the magnetic field drive
signal via the selection circuit SR-C at the time of magnetic field
touch detection. At this time, the ground voltage Vss is supplied
to the drive electrode designated by the other selection signal via
the selection circuit SR-C.
[0163] In addition, the drive signal TSVCOM is supplied to the
drive electrode, which is designated by the selection signal, as
the electric field drive signal via the selection circuit SR-C at
the time of electric field touch detection.
[0164] The selection drive circuit SSL has the same configuration
as the selection drive circuit SSR. That is, the selection drive
circuit SSL is provided with a drive circuit SL-R and a selection
circuit SL-C. The drive circuit SL-R is provided with a shift
register having a plurality of shift stages, and the selection
information SEI is set to the shift register by the control signal
Y-CNT. The set selection information is sequentially shifted in
synchronization with the clock signal CLK.
[0165] When the magnetic field touch detection is designated by the
magnetic field enable signal SC_EN, the drive circuit SL-R forms
and outputs a selection signal according to the selection
information stored in the shift register. The drive circuit SL-R
forms two selection signals according to the selection information
when the magnetic field touch detection is designated. On the other
hand, when the electric field touch detection is designated by the
electric field enable signal TC_EN, the drive circuit SL-R also
forms and outputs a selection signal according to the selection
information stored in the shift register. However, the drive
circuit SR-R forms one selection signal according to the selection
information when the electric field touch detection is
designated.
[0166] The selection circuit SL-C receives the selection signal
from the drive circuit SL-R and connects the drive electrode, which
is designated by the selection signal, to the signal wiring TSV and
the voltage wiring VCOM. That is, the drive electrode, which is
designated by one selection signal from between the two selection
signals, is connected to the voltage wiring VCOM, and the drive
electrode designated by the other selection signal is connected to
the signal wiring TSV at the time of magnetic field touch
detection. On the other hand, the drive electrode designated by the
single selection signal is connected to the signal wiring TSV at
the time of electric field touch detection.
[0167] Accordingly, the ground voltage Vss is supplied to the drive
electrode, which is designated by the one selection signal from
between the two selection signals via the selection circuit SL-C at
the time of magnetic field touch detection. At this time, the drive
signal TSVCOM is supplied to the drive electrode, which is
designated by the other selection signal, as the magnetic field
drive signal via the selection circuit SL-C.
[0168] In addition, the drive signal TSVCOM is supplied to the
drive electrode, which is designated by the selection signal, as
the electric field drive signal via the selection circuit SL-C at
the time of electric field touch detection.
[0169] The selection drive circuit SSR and the selection drive
circuit SSL are configured to operate in synchronization with each
other. Although not particularly limited, the selection drive
circuits SSR and SSL are configured to operate in a synchronized
manner as the same clock signal CLK is supplied to the selection
drive circuits SSR and SSL, and the same control signal Y-CNT is
supplied to the selection drive circuits SSR and SSL in the first
embodiment.
[0170] At the time of magnetic field touch detection, the drive
electrode designated by the selection information in the selection
drive circuit SSR is set to be the same as the drive electrode
designated by the selection information in the selection drive
circuit SSL. In other words, two drive electrodes among the
plurality of drive electrodes are designated by the selection drive
circuits SSR and SSL, respectively, at the time of magnetic field
touch detection. In this case, the drive electrode, which is
connected to the voltage wiring VCOM in the selection circuit SR-C,
is connected to the signal wiring TSV in the selection circuit
SL-C. In addition, the drive electrode, which is connected to the
signal wiring TSV in the selection circuit SR-C, is connected to
the voltage wiring VCOM in the selection circuit SL-C.
[0171] Accordingly, a current depending on a voltage change of the
magnetic field drive signal (the drive signal TSVCOM) flows in each
of the two designated drive electrodes, and the magnetic field is
generated around each of the drive electrodes. In addition,
directions of the respective currents are directly opposite to each
other, and thus the magnetic fields formed by the respective drive
electrodes are superimposed on each other in an area sandwiched by
the two drive electrodes, thereby forming a strong magnetic
field.
[0172] In addition, the same drive electrode is connected to the
signal wiring TSV in each of the selection circuits SR-C and SL-C
at the time of electric field touch detection. Thus, the electric
field drive signal (the drive signal TSVCOM) is supplied to the
designated drive electrode from both end portions thereof, and the
electric field depending on the voltage change of the electric
field drive signal is generated.
[0173] The switching regulator circuit SCX is arranged along the
side 2-U of the display panel 2, and the switching regulator
circuit SCX is coupled with the plurality of signal lines arranged
in the display panel 2 on the side 2-U side. That is, the switching
regulator circuit SCX is connected to the plurality of signal lines
outside the display panel 2. Further, the amplifier circuit AMP is
coupled with the plurality of signal lines arranged in the display
panel 2 via the signal line selector 3 arranged along the side 2-D
of the display panel 2.
[0174] When the magnetic field touch detection is designated by the
magnetic field enable signal SC_EN, the switching regulator circuit
SCX electrically connects predetermined signal lines arranged in
the display panel 2 to each other. Accordingly, the signal lines,
which is arranged in parallel to each other, are connected to each
other on the side 2-U side, and thus a plurality of coils each of
which has a one-turn winding using the signal line as a winding are
formed. Each end portion of the plurality of coils is connected to
the amplifier circuit AMP via the signal line selector 3 on the
side 2-D side. The coil with the one-turn winding functions as the
magnetic field detection coil. That is, a signal change is
generated in the magnetic field detection coil configured using the
signal line depending on the magnetic field generated by the pen in
the magnetic field detection period TDT (FIGS. 2A and 2B). This
signal change is supplied to the amplifier circuit AMP, amplified,
outputted as the sense signals S(0) to S(p), and supplied to the
detection circuit DET.
[0175] In addition, since the signal lines are not connected to
each other via the switching regulator circuit SCX at the time of
electric field touch detection, the amplifier circuit AMP amplifies
the signal change of the signal line, which changes depending on
presence or absence of touch by the finger, and supplies the
amplified signal change to the detection circuit DET as the sense
signals S(0) to S(p).
[0176] The detection circuit processes the supplied sense signals
S(0) to S(p) and supplies the processed sense signals to the
processing circuit PRS. Accordingly, the presence or absence of
touch by the finger, a coordinate of the touch, the pen pressure,
and the like are obtained by the processing circuit PRS and
outputted from the external terminal To at the time of magnetic
field touch detection. In addition, the presence or absence of
touch by the finger, the coordinate of the touch, and the like are
obtained by the processing circuit PRS and outputted from the
external terminal To at the time of electric field touch
detection.
[0177] The description has been given regarding the case where the
magnetic field detection coil has the one-turn winding herein, the
invention is not limited thereto. However, three or more signal
lines may be connected in series by providing the same function as
the switching regulator circuit SCX in the amplifier circuit AMP to
form a coil which has a winding with one and half turns or
more.
<Module Configuration of Display Device 1>
[0178] FIG. 9 is a schematic plan view illustrating an overall
configuration of a module 900 to which the display device 1 is
mounted. FIG. 9 is drawn in accordance with actual arrangement
although being schematic. In FIG. 9, reference numeral 901
represents an area in the TFT glass substrate TGB illustrated in
FIGS. 4A and 4B, and reference numeral 902 represents an area
having the TFT glass substrate TGB and the CF glass substrate CGB
illustrated in FIGS. 4A and 4B. The TFT glass substrate TGB is
integrated with the module 900. That is, the TFT glass substrate
TGB is common to the area 901 and the area 902, and the CF glass
substrate CGB and the like is further formed on an upper surface of
the TFT glass substrate TGB in the area 902 as illustrated in FIGS.
4A and 4B.
[0179] In FIG. 9, numeral 900-U represents a short side of the
module 900, and numeral 900-D represents a side of the module 900,
that is, a short side opposing the short side 900-U. Further,
numeral 900-L represents a long side of the module 900, and numeral
900-R represents a side of the module 900, that is, a long side
opposing the long side 900-L.
[0180] The gate driver 5 and the selection drive circuit SSL
illustrated in FIG. 8 are arranged in an area sandwiched between
the side 2-L of the display panel 2 and the long side 900-L of the
module 900 in the area 902. In addition, the selection drive
circuit SSR illustrated in FIG. 8 is arranged in an area sandwiched
between the side 2-R of the display panel 2 and the long side 900-R
of the module 900 in the area 902. The switching regulator circuit
SCX illustrated in FIG. 8 is arranged in an area sandwiched between
the side 2-U of the display panel 2 and the short side 900-U of the
module 900.
[0181] In addition, the signal line selector 3, the amplifier
circuit AMP, and a drive semiconductor device DDIC illustrated in
FIG. 8 are arranged in an area sandwiched between the side 2-D of
the display panel 2 and the short side 900-D of the module 900.
[0182] In the first embodiment, the signal line driver D-DRV and
the control circuit D-CNT illustrated in FIG. 8 are built in a
single semiconductor device. In the present specification, this
single semiconductor device is illustrated as the drive
semiconductor device DDIC. Further, the touch control device 6
illustrated in FIG. 8 is also built in the single semiconductor
device. In the present specification, the semiconductor device with
the built-in touch control device 6 is referred to also as a touch
semiconductor device 6 to be distinguished from the drive
semiconductor device DDIC. Of course, each of the drive
semiconductor device DDIC and the touch semiconductor device 6 may
be configured using a plurality of semiconductor devices. In
addition, the amplifier circuit AMP may be built in the drive
semiconductor device DDIC, for example.
[0183] In the first embodiment, the amplifier circuit AMP is
arranged in the area 901 and is configured by wirings and parts
formed on the TFT glass substrate TGB in the area 901. The part
includes, for example, a thin film transistor (hereinafter,
referred to also as the TFT transistor). In addition, the drive
semiconductor device DDIC is mounted to the TFT glass substrate so
as to cover the amplifier circuit AMP when seen in a plan view.
Accordingly, it is possible to suppress an increase of a lower
frame of the display panel 2.
[0184] In addition, parts forming the selection drive circuits SSL
and SSR and the switching regulator circuit SCX are also formed on
the TFT glass substrate TGB in the area 902.
[0185] In FIG. 9, numerals FB1 and FB2 represent flexible cables.
Although not particularly limited, the touch semiconductor device 6
is mounted to the flexible cable FB1, and a connector CN is mounted
to the flexible cable FB2. The sense signals S(0) to S(p) described
in FIG. 8 are supplied from the amplifier circuit AMP to the touch
semiconductor device 6 via the connector CN. Further, transmission
and reception of signals are performed between the touch
semiconductor device 6 and the drive semiconductor device DDIC via
the connector CN. The synchronization signal TSHD is drawn in FIG.
9 as an example of the signal to be transmitted and received.
[0186] As already described above, the display panel 2 includes the
pixel array in which the plurality of pixels are arranged in the
matrix form. The pixel array is provided with the plurality of
drive electrodes TL(0) to TL(p) and the scan lines GL(0) to GL(p)
arranged along the row of the array, and the plurality of signal
lines SL(0) to SL(p) arranged along the column of the array. FIG. 9
illustrates two drive electrodes TL(n) and TL(m) and two signal
lines SL(k) and SL(n), for example. Incidentally, FIG. 9 does not
illustrate the scan line. The pixel is arranged at each crossing
portion of the signal lines SL(0) to SL(p) and the scan lines or
the drive electrodes TL(0) to TL(p). Reference signs R, G and B,
which are indicated on the four sides of the display panel 2
illustrated in FIG. 9, represent pixels corresponding to three
primary colors.
[0187] FIG. 10 is a plan view illustrating a relationship between
the drive electrode and the signal line provided in the display
panel 2. Although the display panel 2 includes the drive electrodes
TL(0) to TL(p) and the signal lines SL(0) to SL(p), some of the
drive electrodes and the signal lines are exemplified as drive
electrodes TL(n-6) to TL(n+9) and signal lines SL(n-6) to SL(n+9)
in FIG. 10. Incidentally, FIG. 10 does not illustrate the scan
line.
[0188] When the drive electrode is described by exemplifying the
drive electrodes TL(n-6) to TL(n+9) illustrated in FIG. 10, each of
the drive electrodes includes a first electrode and a plurality of
second electrodes connected to the first electrode. Here, the first
electrode is, for example, a transparent electrode, and the second
electrode is an electrode which has a lower sheet resistance than
the first electrode. In FIG. 10, one second electrode among the
plurality of second electrodes, which are provided in each of the
drive electrodes, is illustrated as an auxiliary electrode SM.
Incidentally, reference sign SM is attached to only the auxiliary
electrodes provided in the drive electrodes TL(n-6) and TL(n+9) in
FIG. 10 to prevent the drawing from being complicated.
[0189] The auxiliary electrode SM also extends in the row direction
of the array, similarly to the first electrode (transparent
electrode) forming the drive electrode, and is electrically
connected to the first electrode. Accordingly, reduction of
combined resistance (impedance) of the drive electrode, which is
provided with the first electrode and the auxiliary electrode
(second electrode), is achieved. In the present specification, the
first electrode (transparent electrode) and the second electrode
(auxiliary electrode SM) connected to the first electrode are
collectively referred to as the drive electrode unless otherwise
specified.
<Structure of Display Panel>
[0190] FIG. 11 is a cross-sectional view illustrating a
configuration of the display panel 2 included in the display device
1 according to the first embodiment. When seen from the viewpoint
of display, an area (first area) inside the display panel 2 is an
area which is active (active area) and is a display area where the
display is performed. On the other hand, an area (second area)
outside the display panel 2 is an area where the display is not
performed, and can be regarded as an area which is non-active
(non-active area) or a peripheral area. When the description is
given by exemplifying FIG. 9, the active area is an area surrounded
by the sides 2-U, 2-D, 2-R and 2-L of the display panel 2.
[0191] FIG. 11 illustrates an A-A' cross section of the display
panel 2 illustrated in FIG. 9. In this first embodiment, one color
pixel is displayed using three pixels corresponding, respectively,
to the three primary colors of R(red), G (green) and B (blue) in
order to perform color display. That is, the one color pixel can be
regarded as being configured using three subpixels. In this case, a
signal line that transfers a color image signal in the display
period is configured using three signal lines. FIG. 11 illustrates
the example of performing color display to illustrate a specific
structure of the display panel 2.
[0192] Reference signs of the signal lines used in FIG. 11 will be
described prior to describing FIG. 11. Each of the signal lines
SL(0) to SL(p) represents the signal line that transfers the color
image signal in the display period. Each of the signal lines
includes three signal lines that transfer the image signal to three
subpixels. FIG. 11 distinguishes the three signal lines by
attaching an alphabetical character of the corresponding subpixel
next to the reference sign of the signal line. When the signal line
SL(n) is exemplified, the signal line SL(n) includes signal lines
SL(n)R, SL(n)G and SL(n)B. Here, the alphabetical character R
attached next to the reference sign SL(n) represents the signal
line that transfers the image signal to the subpixel corresponding
to the red (R) of the three primary colors in the display period.
The alphabetical character G attached next to the reference sign
SL(n) represents the signal line that transfers the image signal to
the subpixel corresponding to the green (G) of the three primary
colors. The alphabetical character B attached next to the reference
sign SL(n) represents the signal line that transfers the image
signal to the subpixel corresponding to the blue (B) of the three
primary colors.
[0193] In FIG. 11, numeral 1100 represents a TFT glass substrate
(TGB in FIGS. 4A and 4B). A first wiring layer (metal wiring layer)
1101 is formed on the TFT glass substrate 1100. A scan line GL(n)
is configured using a wiring formed on the first wiring layer 1101.
An insulating layer 1102 is formed on the first wiring layer 1101,
and second wiring layers (metal wiring layers) 1103 are formed on
the insulating layer 1102. The signal lines SL(n)R, SL(n)G and
SL(n)B, signal lines SL(n+1)R, SL(n+1)G and SL(n+1)B and signal
lines SL(n+2)R and SL(n+2)G are configured using the wirings formed
in the second wiring layers 1103. In FIG. 11, in order to indicate
that these signal lines are configured by the second wiring layers
1103, reference numeral 1103 representing the second wiring layer
is described in [ ] next to the reference signs of the signal
lines. For example, the signal line SL(n)G is indicated by
SL(n)G[1103].
[0194] An insulating layer 1104 is formed on the second wiring
layers 1103, and a third wiring layer (metal wiring layer) 1105 is
formed on the insulating layer 1104. The drive electrode TL(n) and
the auxiliary electrode SM are configured using wirings formed on
the third wiring layer 1105. Here, the drive electrode TL(n) is the
transparent electrode (first electrode). Further, the auxiliary
electrode SM (second electrode) has a lower resistance value than
the drive electrode TL(n), and is formed to be electrically
connected to the drive electrode TL(n). A resistance value of the
drive electrode TL(n), which is the transparent electrode, is
relatively high, but it is possible to reduce the combined
resistance by electrically connecting the auxiliary electrode SM to
the drive electrode TL(n). Here, [1105], which is attached to the
reference signs of the drive electrode and the auxiliary electrode,
also indicates that the electrodes are configured using the third
wiring layer 1105.
[0195] An insulating layer 1106 is formed on the third wiring layer
1105, and pixel electrodes LDP are formed on a top surface of the
insulating layer 1106. In FIG. 11, each reference sign of CR, CB
and CG represents the color filter. A liquid crystal layer 1107 is
sandwiched between the color filters CR (red), CG (green) and CB
(blue) and the insulating layer 1106. Here, the pixel electrode LDP
is provided at a crossing point between the scan line and the
signal line, and the color filter CR, CG or CB corresponding to
each of the pixel electrodes LDP is provided above each of the
point pixel electrodes LDP. A black matrix BM is provided among the
respective color filters CR, CG and CB.
[0196] In addition, the CF glass substrate CGB is formed on the
color filters CR, CG and CB as illustrated in FIGS. 4A, 4B, 6A and
6B although not illustrated in FIG. 11. Further, the detection
electrodes RL(0) to RL(p) and the polarizing plate are formed on
the CF glass substrate CGB as illustrated in FIGS. 4A and 4B.
<Pixel Array>
[0197] Next, a description will be given regarding a circuit
configuration of the display panel 2. FIG. 12 is a circuit diagram
illustrating the circuit configuration of the display panel 2
illustrated in FIGS. 8 and 9. Also in FIG. 12, the signal line is
represented in the same display format as that of FIG. 11. In FIG.
12, each one of a plurality of reference signs SPix, which is
illustrated by one-dot chain line, represents one liquid crystal
display element (subpixel). The subpixels SPix are arranged in a
matrix form in the display panel 2, and configures a liquid crystal
element array (the pixel array) LCD. The pixel array LCD is
provided with the plurality of scan lines GL(0) to GL(p) arranged
in the respective rows and extending in the row direction, and the
signal lines SL(0)R, SL(0)G, SL(0)B to SL(p)R, SL(p)G and SL(p)B
arranged in the respective columns and extending in the column
direction. In addition, the pixel array LCD includes the drive
electrodes TL(0) to TL(p) arranged in the respective rows and
extending in the row direction.
[0198] FIG. 12 illustrates only a part of the pixel array relating
to scan lines GL(n-1) to GL(n+1), the signal lines SL(n)R, SL(n)G,
SL(n)B to SL(n+1)R, SL(n+1)G and SL(n+1)B, and drive electrodes
TL(n-1) to TL(n+1). To make the description easy in FIG. 12, the
drive electrodes TL(n-1) to TL(n+1) is shown to be arranged in the
respective rows, but one drive electrode may be arranged with
respect to a plurality of rows.
[0199] Each of the subpixels SPix, which are arranged at crossing
points among the row and the column of the pixel array LCD, is
provided with a TFT transistor Tr formed on the TFT glass substrate
1100 and a liquid crystal element LC of which one terminal is
connected to a source of the TFT transistor Tr. In the pixel array
LCD, gates of the TFT transistors Tr of the plurality of subpixels
SPix arranged in the same row are connected to the scan line
arranged in the same row, and drains of the TFT transistors Tr of
the plurality of subpixels SPix arranged in the same column are
connected to the signal line arranged in the same column. In other
words, the plurality of subpixels SPix are arranged in the matrix
form; the scan lines are arranged in the respective rows; and the
plurality of subpixels SPix arranged in the corresponding row are
connected to the scan line. Further, the signal lines are arranged
in the respective columns, and the subpixels SPix arranged in the
corresponding column are connected to the signal line. Further, the
other ends of the liquid crystal elements LC of the plurality of
subpixels SPix arranged in the same row are connected to the drive
electrode arranged in the row.
[0200] When the description is given with the example illustrated
in FIG. 12, the respective gates of the TFT transistors Tr of the
plurality of subpixels SPix arranged on an uppermost row are
connected to the scan line GL(n-1) arranged in the uppermost row in
FIG. 12. Further, the respective drains of the TFT transistors Tr
of the plurality of subpixels SPix arranged in a leftmost column
are connected to the signal line SL(n)R arranged in the leftmost
column in FIG. 12. Further, the respective other ends of the liquid
crystal elements LC of the plurality of subpixels SPix arranged in
the uppermost row are connected to the drive electrode TL(n-1)
arranged in the uppermost row in FIG. 12.
[0201] As described above, the single subpixel SPix corresponds to
one of the three primary colors. Accordingly, the three primary
colors of R, G and B are configured using the three subpixels SPix.
In FIG. 12, one color pixel Pix is formed using the three subpixels
SPix, which are successively arranged in the same row, and color is
expressed by the relevant pixel Pix. That is, the subpixel SPix
indicated by 1200R is set as a subpixel SPix(R) of R(red); the
subpixel SPix indicated by 1200G is set as a subpixel SPix(G) of G
(green); and the subpixel SPix indicated by 1200B is set as a
subpixel SPix(B) of B (blue) in FIG. 12. Accordingly, the color
filter CR for red is provided as the color filter in the subpixel
SPix(R) indicated by 1200R; the color filter CG for green is
provided as the color filter in the subpixel SPix(G) indicated by
1200G; and the color filter CB for blue is provided as the color
filter in the subpixel SPix(B) indicated by 1200B.
[0202] Further, among the signals each of which indicates the
single pixel, an image signal corresponding to R (red) is supplied
from the signal line selector 3 to the signal line SL(n)R; an image
signal corresponding to G (green) is supplied from the signal line
selector 3 to the signal line SL(n)G; and an image signal
corresponding to B (blue) is supplied from the signal line selector
3 to the signal line SL(n)B.
[0203] The TFT transistor Tr of each of the subpixels SPix is an
N-channel TFT transistor although not particularly limited thereto.
Pulsed scan line signals are supplied from the gate driver 5 (FIGS.
8 and 9) to the scan lines GL(0) to GL(p), which sequentially
become high levels in this order. That is, voltages of the scan
lines sequentially become high levels from the scan line GL(0)
arranged in the upper row toward the scan line GL(p) arranged in
the lower row in the pixel array LCD. Accordingly, the TFT
transistors Tr in the subpixels SPix are sequentially turned into
the on-state (conductive state) from the subpixel SPix arranged in
the upper row toward the subpixel SPix arranged in the lower row in
the pixel array LCD.
[0204] When the TFT transistor Tr is turned into the on-state, the
image signal supplied to the signal line is supplied to the liquid
crystal element LC via the TFT transistor that is in the conductive
state at the time. The electric field of the liquid crystal element
LC is changed depending on a gap voltage between a voltage of the
display drive signal supplied to the drive electrodes TL(0) to
TL(p) and a voltage of the supplied image signal, and the
modulation of light passing through the liquid crystal element LC
is changed. Accordingly, a color image, which corresponds to the
image signals supplied to the signal lines SL(0)R, SL(0)G, SL(n)B
to SL(p)R, SL(p)G, and SL(p)B in synchronization with the scan line
signal supplied to the scan lines GL(0) to GL(p), is displayed on
the display panel 2.
[0205] Each of the plurality of subpixels SPix can be regarded as
including a selection terminal and a pair of terminals. In this
case, the gate of the TFT transistor Tr configuring the subpixel
SPix is the selection terminal of the subpixel SPix; the drain of
the TFT transistor Tr is one terminal between the pair of
terminals; and the other end of the liquid crystal element LC is
the other terminal of the subpixel SPix.
[0206] Here, a correspondence between the arrangement of the
display panel 2 illustrated in FIGS. 8 and 9 and the circuit
diagram illustrated in FIG. 12 will be described as follows.
[0207] The pixel array LCD includes a pair of sides substantially
parallel to the row of the array, and a pair of sides substantially
parallel to the column of the array. The pair of sides parallel to
the row of the pixel array LCD are a first side and a second side
corresponding to the short sides 2-U and 2-D of the display panel 2
illustrated in FIGS. 8 and 9; and the pair of sides parallel to the
column of the pixel LCD are a third side and a fourth side
corresponding to the long sides 2-L and 2-R of the display panel
2.
[0208] As illustrated in FIG. 9, the signal line selector 3, the
amplifier circuit AMP, and the drive semiconductor device DDIC are
arranged along the second side out of the pair of sides parallel to
the row, that is, the short side 2-D of the display panel 2 in the
pixel array LCD. The image signal from the drive semiconductor
device DDIC is supplied to the signal lines SL(0)R, SL(0)G, SL(0)B
to SL(p)R, SL(p)G and SL(p)B via the signal line selector 3 on the
second side (the short side 2-D of the display panel 2) in the
pixel array LCD.
[0209] In addition, the switching regulator circuit SCX is arranged
along the first side of the pixel array LCD, that is, the other
side (the short side 2-U) of the display panel 2 as illustrated in
FIG. 9.
[0210] Further, the gate driver 5 and the selection drive circuit
SSL are arranged along the third side out of the pair of sides
parallel to the column (the third side and the fourth side), that
is, the long side 2-L of the display panel 2 in the pixel array
LCD. The scan line signal from the gate driver 5 is supplied to the
scan lines GL(0) to GL(p) on the third side in the pixel array LCD.
Although the gate driver 5 is arranged along the long side 2-L of
the display panel 2 in FIG. 9, the gate driver 5 may be divided
into two parts to be arranged along the long side 2-L (the third
side of the pixel array LCD) and the long side 2-R (the fourth side
of the pixel array LCD), respectively. In addition, the display
drive signal is supplied from the selection drive circuit SSL to
the drive electrode on the third side in the pixel array LCD in the
display period. Further, the magnetic field drive signal or the
electric field drive signal is supplied from the selection drive
circuit SSL to the designated drive electrode on the third side in
the magnetic field generation period TGT for the magnetic field
touch detection or at the time of electric field touch
detection.
[0211] The selection drive circuit SSR is arranged along the fourth
side of the pixel array LCD, that is, the long side 2-R of the
display panel 2 as illustrated in FIG. 9. In the display period,
the display drive signal is supplied from the selection drive
circuit SSR to the common electrode on the fourth side. On the
other hand, the magnetic field drive signal or the electric field
drive signal is also supplied to the designated drive electrode
from the fourth side, similarly to the above-described selection
drive circuit SSL, at the time of the magnetic field touch
detection or electric field touch detection.
[0212] Although the pixel array LCD of a case where the color
display is performed in the display panel 2 has been described
concretely, the pixel array LCD may be regarded as being configured
by the plurality of color pixels Pix (pixels) each of which is
configured using the three subpixels SPix. When regarded as above,
the plurality of pixels Pix are arranged in a matrix form, thereby
configuring the pixel array LCD. The corresponding scan lines GL(0)
to GL(p) and the corresponding drive electrodes TL(0) to TL(p) are
arranged in the respective rows of the pixel array LCD configured
by the pixels Pix, and the signal lines SL(0) to SL(p) are arranged
in the respective columns thereof.
[0213] In this case, the three subpixels SPix are regarded as a
single pixel Pix, and the pixel Pix is regarded as having the same
configuration as the subpixel SPix. The respective selection
terminals of the pixels Pix arranged in the matrix form in the
pixel array LCD are connected to the scan lines GL(0) to GL(p)
arranged in the same row as the pixels Pix; the respective one-side
terminals of the pixels Pix are connected to the signal lines SL(0)
to SL(p) arranged in the same column; and the respective other-side
terminals of the pixels Pix are connected to the drive electrodes
TL(0) to TL(p) arranged in the same column. Of course, one drive
electrode may correspond to a plurality of columns of the pixel
array LCD. In such a case, the other terminals of the pixels Pix
arranged in the plurality of rows are connected to the common drive
electrode.
[0214] Even in the case where it is regarded that the pixel array
LCD is regarded as being configured by the plurality of pixels Pix
in this manner, the correspondence between the arrangement of the
display panel 2 illustrated in FIGS. 8 and 9 and the circuit
diagram illustrated in FIG. 12 is the same as the content that has
been described above.
[0215] Although the description has been given with the case where
the number of the subpixels SPix configuring the single color pixel
Pix is three, the number is not limited thereto. One color pixel
may be configured using, for example, subpixels of white (W) and
yellow (Y) in addition to R, G and B described above, or subpixels
that additionally include any one or a plurality of colors among
complementary colors (cyan (C), magenta (M) and yellow (Y)) of R, G
and B described above.
<Selection Drive Circuit>
[0216] Next, the configurations and operations of the selection
drive circuits SSL and SSR in the display device 1 according to the
first embodiment will be described with reference to FIGS. 13 to
18.
<<Overview of Operation of Selection Drive
Circuit>>
[0217] First, the overview of the operation will be described in
order to facilitate the understanding of the selection drive
circuit. In the first embodiment, the selection drive circuit SSR
is provided with the drive circuit SR-R and the selection circuit
SR-C as illustrated in FIG. 8. The drive circuit SR-R forms a
selection signal to designate a drive electrode which generates a
strong magnetic field in the magnetic field generation period TGT
for the magnetic field touch detection. In addition, the drive
circuit SR-R forms a selection signal to designate a drive
electrode which generates an electric field at the time of electric
field touch detection. The selection circuit SR-C connects drive
electrodes, which sandwich the designated drive electrode, to the
signal wiring TSV and the voltage wiring VCOM so that the magnetic
field is generated around the drive electrode designated by the
selection signal in the magnetic field generation period TGT. In
addition, the selection circuit SR-C connects the drive electrode
designated by the selection signal to the signal wiring TSV at the
time of electric field touch detection.
[0218] The drive circuit SR-R includes the plurality of unit drive
circuits USR(0) to USR(p) each of which has the shift stage, and
the shift register is configured by connecting the unit drive
circuits USR(0) to USR(p) in series. At each time of magnetic field
touch detection and electric field touch detection, the selection
information, which designates the drive electrode to be selected,
is shifted in the shift register configured by the plurality of
unit drive circuits, and so the drive circuit SR-R forms the
selection signals which sequentially designate the drive
electrodes.
[0219] The selection drive circuit SSL is also provided with the
drive circuit SL-R and the selection circuit SL-C similarly to the
selection drive circuit SSR. The drive circuit SL-R includes the
plurality of unit drive circuits USL(0) to USL(p) similarly to the
drive circuit SR-R, and operates in the same manner as the drive
circuit SR-R. In addition, the selection circuit SL-C operates in
the same manner as the selection circuit SR-C.
[0220] FIG. 13 is an explanatory diagram illustrating a touch
detection operation in the display device 1 according to the first
embodiment. FIG. 13A illustrates a case where the touch detection
operation is the electric field touch detection, and FIG. 13B
illustrates a case where the touch detection operation is the
magnetic field touch detection. FIG. 13 illustrates the unit drive
circuit USR(n) among the plurality of unit drive circuits USR(0) to
USR(p) forming the drive circuit SR-R and the unit drive circuit
USL(n) among the plurality of unit drive circuits USL(0) to USL(p)
forming the drive circuit SL-R to describe the overview of
operation, and does not illustrate the selection circuits SR-C and
SL-C.
[0221] Each of the unit drive circuits USR(0) to USR(p) and USL(0)
to USL(p) corresponds to each of the drive electrodes TL(0) to
TL(p) arranged to be parallel to each other, but the unit drive
circuits and the drive electrodes may not necessarily have
one-to-one correspondence. That is, a plurality of drive
electrodes, which are arranged to be adjacent to each other, may
correspond to the unit drive circuit. FIG. 13 illustrates an
example where six drive electrodes correspond to the unit drive
circuit. That is, six drive electrodes TL(n)-1 to TL(n)-6, which
are arranged to be proximate and adjacent to each other, are
regarded as one drive electrode TL(n) and correspond to the unit
drive circuits USR(n) and USL(n).
[0222] When the unit drive circuits USR(n) and USL(n) form the
selection signal which designates the corresponding drive electrode
TL(n) in the electric field touch detection, one end portion of
each of the designated drive electrode TL(n), that is, the six
drive electrodes TL(n)-1 to TL(n)-6 is connected to the signal
wiring TSV on the side 2-L (FIGS. 8 and 9) side. In addition, the
other end portion of each of the designated drive electrode TL(n),
that is, the six drive electrodes TL(n)-1 to TL(n)-6 is connected
to the signal wiring TSV on the side 2-R (FIGS. 8 and 9) side.
Since the drive signal TSVCOM with the periodically changing
voltage is supplied to the signal wiring TSV at the time of
electric field touch detection, the drive signal TSVCOM is supplied
as the electric field drive signal to both the ends of the drive
electrode TL(n), that is, the six drive electrodes TL(n)-1 to
TL(n)-6. As a result, the electric field is generated according to
the electric field drive signal (the drive signal TSVCOM).
[0223] On the other hand, when the unit drive circuits USR(n) and
USL(n) form the selection signal which designates the corresponding
drive electrode TL(n) in the magnetic field generation period TGT
for the magnetic field touch detection, the designated drive
electrode TL(n), that is, the drive electrodes TL(n-1) and TL(n+1)
arranged to sandwich the six drive electrodes TL(n)-1 to TL(n)-6
are connected to the signal wiring TSV and the voltage wiring VCOM.
The drive electrode TL(n-1) is configured by six drive electrodes
TL(n-1)-1 to TL(n-1)-6, and the drive electrode TL(n+1) is also
configured by six drive electrodes TL(n+1)-1 to TL(n+1)-6. FIG. 13
illustrates only the drive electrodes TL(n-1)-5, TL(n-1)-6,
TL(n+1)-1 and TL(n+1)-2 among these drive electrodes, and does not
illustrate the remaining drive electrodes TL(n-1)-1 to TL(n-1)-4
and TL(n+1)-3 to TL(n+1)-6.
[0224] When the description is given by exemplifying the drive
electrodes TL(n-1)-5, TL(n-1)-6, TL(n+1)-1 and TL(n+1)-2
illustrated in FIG. 13, one end portion of each of the drive
electrodes TL(n-1)-5 and TL(n-1)-6 is connected to the signal
wiring TSV on the side 2-L side. In addition, one end portion of
each of the drive electrodes TL(n+1)-1 and TL(n+1)-2 is connected
to the voltage wiring VCOM on the side 2-L side. At this time, the
other end portion of each of the drive electrodes TL(n-1)-5 and
TL(n-1)-6 is connected to the voltage wiring VCOM on the side 2-R
side, and the other end portion of each of the drive electrodes
TL(n+1)-1 and TL(n+1)-2 is connected to the signal wiring TSV on
the side 2-R side. Similarly, one end portion of each of the drive
electrodes TL(n-1)-1 to TL(n-1)-4 (not illustrated) is also
connected to the signal wiring TSV on the side 2-L side, and the
other end portion thereof is connected to the voltage wiring VCOM
on the side 2-R side. In addition, one end portion of each of the
drive electrodes TL(n+1)-3 to TL(n+1)-6 (not illustrated) is
connected to the voltage wiring VCOM on the side 2-L side, and the
other end portion thereof is connected to the signal wiring TSV on
the side 2-R side.
[0225] In the magnetic field generation period TGT for the magnetic
field touch detection, the drive signal TSVCOM with the
periodically changing voltage is supplied to the signal wiring TSV,
and the ground voltage Vss is supplied to the voltage wiring VCOM.
Thus, a current indicated by the arrow I1 flows in the drive
electrode TL(n-1) out of the drive electrodes TL(n-1) and TL(n+1)
arranged with the designated drive electrode TL(n) sandwiched
therebetween, and a current I2 in an opposite direction to the
current I1 flows in the drive electrode TL(n+1) as indicated by the
arrow, as illustrated in FIG. 13. That is, the currents in the
directions opposite to each other flow, respectively, in the drive
electrodes TL(n-1) and TL(n+1) that are arranged with the
designated drive electrode TL(n) sandwiched therebetween, according
to the voltage change of the magnetic field drive signal (the drive
signal TSVCOM). Accordingly, the magnetic field generated around
the drive electrode TL(n-1) and the magnetic field generated around
the drive electrode TL(n+1) are superimposed on each other in the
area where the drive electrode TL(n) is arranged, thereby
generating a strong magnetic field.
[0226] In addition, the six drive electrodes TL(n-1)-1 to TL(n-1)-6
are provided as a bundle to form the drive electrode TL(n-1) so
that the magnetic field generated around the drive electrode
TL(n-1) becomes strong in the example illustrated in FIG. 13.
Similarly, the six drive electrodes TL(n+1)-1 to TL(n+1)-6 are
provided as a bundle to form the drive electrode TL(n+1) so that
the magnetic field generated around the drive electrode TL(n+1)
becomes strong. As a result, it is possible to further strengthen
the superimposed magnetic field.
[0227] In this manner, it is possible to generate the strong
magnetic field without forming the coil by connecting in series the
drive electrode TL(n-1) and the drive electrode TL(n+1) which are
arranged to be parallel to each other. As a result, the control
becomes easy, and it is further possible to suppress the increase
of the area occupied by the control circuit.
<<Configuration of Selection Drive Circuit>>
[0228] FIG. 14 is a block diagram illustrating each configuration
of the selection drive circuits SSL and SSR according to the first
embodiment. The selection drive circuit SSL and the selection drive
circuit SSR have the configurations similar to each other. First,
the configuration of the selection drive circuit SSL will be
described, and the selection drive circuit SSR will be described by
mainly focusing on a different point from the selection drive
circuit SSL.
[0229] The selection drive circuit SSL is provided with the drive
circuit SL-R and the selection circuit SL-C as illustrated in FIG.
8. The drive circuit SL-R includes the plurality of unit drive
circuits USL(0) to USL(p) which correspond, respectively, to the
drive electrodes TL(0) to TL(p), and the selection circuit SL-C
includes: a plurality of third switches and fourth switches
corresponding to each of the drive electrodes TL(0) to TL(p); and
the switch control circuit SWL. FIG. 14 illustrates the drive
electrodes TL(n) to TL(n+5) among the drive electrodes TL(0) to
TL(p), and a part of the selection drive circuit SSL which
corresponds to these drive electrodes TL(n) to TL(n+5).
Hereinafter, the selection drive circuit SSL will be described by
exemplifying the part thereof which corresponds to the drive
electrodes TL(n) to TL(n+5).
[0230] In FIG. 14, numerals USL(n) to USL(n+5) represent the unit
drive circuits which correspond to the drive electrodes TL(n) to
TL(n+5). Each of the unit drive circuits USL(n) to USL(n+5) has the
shift stage. The respective shift stages of the unit drive circuits
USL(n) to USL(n+5) are connected in series, thereby forming the
shift register. The selection information SEI is supplied to the
unit drive circuit USL(n) from the unit drive circuit USL (not
illustrated) at the previous stage of the unit drive circuit USL(n)
in the magnetic field generation period TGT and the electric field
touch detection period. The selection information SEI is shifted in
the shift register, which is configured by the shift stages of the
unit drive circuits USL(n) to USL(n+5), in synchronization with the
clock signal CLK, and is shifted from the unit drive circuit USL(n)
toward the unit drive circuit USL(n+5). In addition, when the
selection information SEI is shifted, the selection signal is
outputted to the switch control circuit SWL from each of the unit
drive circuits USL(n) to USL(n+5).
[0231] The switch control circuit SWL receives: the selection
signals from the unit drive circuits USL(n) to USL(n+5); the
magnetic field enable signal SC_EN; and the electric field enable
signal TC_EN, and forms a first drive signal which performs switch
control of third switches STLn to STLn+5 and a second drive signal
which performs switch control of fourth switches SVLn to
SVLn+5.
[0232] Each of the third switches STLn to STLn+5 and the fourth
switches SVLn to SVLn+5 corresponds to each of the drive electrodes
TL(n) to TL(n+5). For example, the third switch STLn and the fourth
switch SVLn correspond to the drive electrode TL(n), and the third
switch STLn+5 and the fourth switch SVLn+5 correspond to the drive
electrode TL(n+5). Each of the remaining third switch and fourth
switch also corresponds to the drive electrode one to one in the
same manner.
[0233] Each of the third switches STLn to STLn+5 is connected
between the signal wiring TSV and one end portion of each of the
corresponding drive electrodes TL(n) to TL(n+5) on the side 2-L
side of the display panel 2, and is subjected to the switch control
according to the first drive signal. Further, each of the fourth
switches SVLn to SVLn+5 is connected between the voltage wiring
VCOM and one end portion of each of the corresponding drive
electrodes TL(n) to TL(n+5) on the side 2-L side of the display
panel 2, and is subjected to the switch control according to the
second drive signal. When the description is given by exemplifying
the third switches STLn and STLn+5 and the fourth switches SVLn and
SVLn+5, the third switch STLn is connected between the signal
wiring TSV and the one end portion of the drive electrode TL(n) on
the side 2-L side, and the fourth switch SVLn is connected between
the voltage wiring VCOM and the one end portion of the drive
electrode TL(n) on the side 2-L side. In addition, the third switch
STLn+5 is connected between the signal wiring TSV and the one end
portion of the drive electrode TL(n+5) on the side 2-L side, and
the fourth switch SVLn+5 is connected between the voltage wiring
VCOM and one end portion of the drive electrode TL(n+5) on the side
2-L side. The remaining third switch and fourth switch are also
configured in the same manner.
[0234] In the first embodiment, the selection circuit SL-C
illustrated in FIG. 8 is configured using the third switches STLn
to STLn+5, the fourth switches SVLn to SVLn+5, and the switch
control circuit SWL.
[0235] In the selection drive circuit SSR, numerals USR(n) to
USR(n+5) are unit drive circuits which correspond to the
above-described unit drive circuits USL(n) to USL(n+5), and numeral
SWR is a switch control circuit which corresponds to the
above-described switch control circuit SWL. In addition, numerals
STRn to STRn+5 are fifth switches which correspond to the
above-described third switches STLn to STLn+5, and numerals SVRn to
SVRn+5 are sixth switches which correspond to the above-described
fourth switches SVLn to SVLn+5.
[0236] The shift stages in the unit drive circuits USR(n) to
USR(n+5) are connected in series, and the selection information SEI
is shifted from the unit drive circuit USR(n) to USR(n+5) in
synchronization with the clock signal CLK. At the time of being
shifted, the selection information SEI stored in the unit drive
circuits USR(n) to USR(n+5) is outputted to the switch control
circuit SWR as the selection signals of the unit drive circuits
USR(n) to USR(n+5). The switch control circuit SWR receives: the
selection signal from the unit drive circuits USR(n) to USR(n+5);
the magnetic field enable signal SC_EN; and the electric field
enable signal TC_EN, and forms a third drive signal which performs
switch control of the fifth switches STRn to STRn+5 and a fourth
drive signal which performs switch control of the sixth switches
SVLn to SVLn+5.
[0237] The drive circuit SR-R configured using the unit drive
circuits USR(n) to USR(n+5) and the selection circuit SR-C
configured using the fifth switch, the sixth switch, and the switch
control circuit SWR are arranged along the side 2-R of the display
panel 2 as illustrated in FIG. 8. Thus, each of the fifth switches
STRn to STRn+5 is connected between the signal wiring TSV and the
other end portion of each of the corresponding drive electrodes
TL(n) to TL(n+5) on the side 2-R side. In addition, each of the
sixth switches SVRn to SVRn+5 is connected between the voltage
wiring VCOM and the other end portion of each of the corresponding
drive electrodes TL(n) to TL(n+5) on the side 2-R side.
[0238] When the description is given by exemplifying the fifth
switches STRn and STRn+5 and the sixth switches SVRn and SVRn+5,
the fifth switch STRn is connected between the signal wiring TSV
and the other end portion of the drive electrode TL(n) on the side
2-R side, and the sixth switch SVRn is connected between the
voltage wiring VCOM and the other end portion of the drive
electrode TL(n) on the side 2-R side. In addition, the fifth switch
STRn+5 is connected between the signal wiring TSV and the other end
portion of the drive electrode TL(n+5) on the side 2-R side, and
the sixth switch SVRn+5 is connected between the voltage wiring
VCOM and the other end portion of the drive electrode TL(n+5) on
the side 2-R side. The remaining fifth switch and sixth switch are
also configured in the same manner.
[0239] The periodically changing drive signal TSVCOM is supplied to
the signal wiring TSV at the time of the magnetic field touch
detection in the magnetic field generation period TGT. In addition,
the ground voltage Vss is supplied to the voltage wiring VCOM at
this time. FIGS. 15A to 15C are waveform diagrams illustrating a
waveform of each voltage supplied to the signal wiring TSV and the
voltage wiring VCOM in the magnetic field generation period TGT. In
FIGS. 15A to 15C, the horizontal axis represents time t, and the
vertical axis represents a voltage. FIG. 15A illustrates a waveform
of the drive signal TSVCOM supplied to the signal wiring TSV
arranged in the selection circuit SL-C, and FIG. 15B illustrates a
waveform of the drive signal TSVCOM supplied to the signal wiring
TSV arranged in the selection circuit SR-C. In addition, FIG. 15C
illustrates a voltage waveform of the voltage wiring VCOM arranged
in the selection circuits SL-C and SR-C.
[0240] As illustrated in FIGS. 15A to 15C, the drive signal TSVCOM
supplied to the selection circuit SL-C and the drive signal TSVCOM
supplied to the selection circuit SR-C are synchronized with each
other, and each voltage value periodically changes between the
ground voltage Vss and a predetermined voltage (first voltage) Vp.
On the other hand, the ground voltage Vss is supplied to the
voltage wiring VCOM.
[0241] The drive signals synchronized with each other are also
supplied to the signal wiring TSV arranged in the selection circuit
SL-C and the signal wiring TSV arranged in the selection circuit
SR-C at the time of electric field touch detection as illustrated
in FIGS. 15A and 15B. Although not particularly limited, the
predetermined voltage Vp of the drive signal TSVCOM is different
between the magnetic field generation period TGT and the time of
electric field touch detection. In addition, a period of the drive
signal TSVCOM illustrated in FIGS. 15A and 15B is also different
between the magnetic field generation period TGT and the electric
field touch detection period. Of course, the predetermined voltage
Vp and the period may be the same therebetween without being
limited thereto.
[0242] The switch control circuits SWL and SWR operate differently
between a case where the magnetic field touch detection is
designated by the magnetic field enable signal SC_EN and a case
where the electric field touch detection is designated by the
electric field enable signal TC_EN. The operation in the case where
the magnetic field touch detection is designated will be described
with reference to FIGS. 16 and 17, and the operation in the case
where the electric field touch detection is designated will be
described with reference to FIG. 18.
<<Operation of Magnetic Field Generation>>
[0243] FIGS. 16 and 17 are schematic plan views illustrating the
operation in the case where the magnetic field touch detection is
designated.
[0244] When the selection signal supplied from the unit drive
circuit indicates selection, the switch control circuit SWL
controls the third switch and the fourth switch so that two drive
electrodes arranged to sandwich the drive electrode corresponding
to the unit drive circuit which outputs the selection signal
indicating the selection are connected to the signal wiring TSV and
the voltage wiring VCOM. Although not particularly limited, the
switch control circuit SWL controls the third switch to connect the
drive electrode, which is closer to the side 2-U out of the two
drive electrodes, to the signal wiring TSV, and the switch control
circuit SWL controls the fourth switch to connect the drive
electrode, which is closer to the side 2-D, to the voltage wiring
VCOM in the first embodiment.
[0245] Similarly, the switch control circuit SWR also controls the
sixth switch and the fifth switch when the selection signal
supplied from the unit drive circuit indicates selection so that
two drive electrodes arranged to sandwich the drive electrode
corresponding to the unit drive circuit which outputs the selection
signal indicating the selection are connected to the voltage wiring
VCOM and the signal wiring TSV. In the first embodiment, the switch
control circuit SWR controls the sixth switch to connect the drive
electrode, which is closer to the side 2-U out of the two drive
electrodes, to the voltage wiring VCOM, and the switch control
circuit SWL controls the fifth switch to connect the drive
electrode, which is closer to the side 2-D, to the signal wiring
TSV.
[0246] The shift register configured using the unit drive circuits
USL(n) to USL(n+5) and the shift register configured using the unit
drive circuits USR(n) to USR(n+5) operate in synchronization with
each other. Thus, the drive electrode whose one end portion is
connected to the signal wiring TSV by the switch control circuit
SWL has the other end portion which is connected to the voltage
wiring VCOM by the switch control circuit SWR. In addition, the
drive electrode whose other end portion is connected to the signal
wiring TSV by the switch control circuit SWR has one end portion
which is connected to the voltage wiring VCOM by the switch control
circuit SWL.
[0247] FIG. 16 illustrates a state where the unit drive circuit
USL(n+2) and the unit drive circuit USR(n+2) output the selection
signal indicating the selection. The drive electrode corresponding
to the unit drive circuits USL(n+2) and USR(n+2) is the drive
electrode TL(n+2), and thus two drive electrodes arranged to
sandwich the drive electrode TL(n+2) are the drive electrode
TL(n+1) and the drive electrode TL(n+3). The switch control circuit
SWL turns the third switch STLn+1 into the on-state by the first
drive signal so that one end portion of the drive electrode TL(n+1)
arranged to be closer to the side 2-U out of the two drive
electrodes is connected to the signal wiring TSV. At this time, the
switch control circuit SWL turns the fourth switch SVLn+3 into the
on-state by the second drive signal so that one end portion of the
drive electrode TL(n+3) arranged to be closer to the side 2-D is
connected to the voltage wiring VCOM.
[0248] In addition, the switch control circuit SWL performs control
using the first drive signal so that the remaining third switches
STLn and STLn+2 to STLn+5, except for the third switch STLn+1, are
turned into the off-state. Similarly, the switch control circuit
SWL performs control using the second drive signal so that the
remaining fourth switches SVLn to SVLn+2, SVLn+4 to SVLn+5, except
for the fourth switch SVLn+3, are turned into the off-state.
[0249] On the other hand, the switch control circuit SWR turns the
sixth switch SVRn+1 into the on-state by the fourth drive signal so
that the other end portion of the drive electrode TL(n+1) arranged
to be closer to the side 2-U out of the two drive electrodes is
connected to the voltage wiring VCOM. At this time, the switch
control circuit SWR turns the fifth switch STRn+3 into the on-state
by the third drive signal so that the other end portion of the
drive electrode TL(n+3) arranged to be closer to the side 2-D is
connected to the signal wiring TSV.
[0250] In addition, the switch control circuit SWR performs control
using the third drive signal so that the remaining fifth switches
STRn to STRn+2, STRn+4 to STLn+5, except for the fifth switch
STRn+3, are turned into the off-state at this time. Similarly, the
switch control circuit SWR performs control using the fourth drive
signal so that the remaining sixth switches SVLn, SVRn+2 to SVRn+5,
except for the sixth switch SVRn+1, are turned into the
off-state.
[0251] Accordingly, the drive electrode TL(n+1) out of the two
drive electrodes arranged to sandwich the drive electrode TL(n+2)
has the one end portion connected to the signal wiring TSV and the
other end portion connected to the voltage wiring VCOM. At this
time, the other drive electrode TL(n+3) has the one end portion
connected to the voltage wiring VCOM and the other end portion
connected to the signal wiring TSV. As illustrated in FIGS. 15A to
15C, when the drive signal TSVCOM whose voltage value periodically
changes is supplied to the signal wiring TSV and the ground voltage
Vss is supplied to the voltage wiring VCOM, the current I1
indicated by arrow in FIG. 16 flows in the drive electrode TL(n+1),
and the current I2 indicated by the arrow flows in the drive
electrode TL(n+3).
[0252] When the current I1 flows, the magnetic field .PHI.I1
indicated by the broken-line arrow is generated around the drive
electrode TL(n+1). Meanwhile, the current I2 in the opposite
direction to the current I1 flows in the drive electrode TL(n+3),
and accordingly the magnetic field .PHI.I2 indicated by the
broken-line arrow is generated around the drive electrode TL(n+3).
Since the drive electrode TL(n+2) is sandwiched between the drive
electrodes TL(n+1) and TL(n+3), the magnetic field .PHI.I1 and the
magnetic field .PHI.I2 are superimposed on each other in an area of
the drive electrode TL(n+2), thereby generating a strong magnetic
field. In addition, each of the drive electrodes TL(n), TL(n+2),
TL(n+4) and TL(n+5), except for the drive electrodes TL(n+1) and
TL(n+3), are in the floating state at this time.
[0253] The selection information SEI indicating the selection is
shifted from the unit drive circuits USL(n+2) and USR(n+2) to the
unit drive circuits USL(n+3) and USR(n+3) as a clock signal CLK
changes. Through such shift, the area where the strong magnetic
field is generated is changed from an area of the drive electrode
TL(n+2) to an area of the drive electrode TL(n+3). FIG. 17
illustrates a state where the strong magnetic field is generated
around the drive electrode TL(n+3).
[0254] As the clock signal CLK changes, the selection information
SEI indicating the selection is shifted to the unit drive circuits
USL(n+3) and USR(n+3). The drive electrode corresponding to the
unit drive circuits USL(n+3) and USR(n+3) is the drive electrode
TL(n+3). Thus, the switch control circuits SWL and SWR connect the
drive electrode TL(n+2), which is arranged to be more proximate to
the side 2-U than the drive electrode TL(n+3), to the signal wiring
TSV and the voltage wiring VCOM. In addition, the switch control
circuits SWL and SWR connect the drive electrode TL(n+4), which is
arranged to be more proximate to the side 2-D than the drive
electrode TL(n+3), to the voltage wiring VCOM and the signal wiring
TSV at this time. That is, the switch control circuit SWL turns the
third switch STLn+2 into the on-state using the first drive signal;
the fourth switch SVLn+4 into the on-state using the second drive
signal; and the remaining third switch and fourth switch into the
off-state. In addition, the switch control circuit SWR turns the
fifth switch SVRn+2 into the on-state using the third drive signal;
the sixth switch STRn+4 into the on-state using the fourth drive
signal; and the remaining fifth switch and sixth switch into the
off-state.
[0255] As a result, one end portion of the drive electrode TL(n+2)
is connected to the signal wiring TSV via the third switch STLn+2,
and the other end portion thereof is connected to the voltage
wiring VCOM via the fifth switch SVRn+2. At this time, one end
portion of the drive electrode TL(n+4) is connected to the voltage
wiring VCOM via the fourth switch SVLn+4, and the other end portion
thereof is connected to the signal wiring TSV via the sixth switch
SVRn+2. When the drive signal TSVCOM is supplied to the signal
wiring TSV and the ground voltage Vss is supplied to the voltage
wiring VCOM, the current I1 indicated by arrow in FIG. 17 flows in
the drive electrode TL(n+2), and the current I2 indicated by the
arrow flows in the drive electrode TL(n+4).
[0256] When the currents I1 and I2 flow, the magnetic field .PHI.I1
indicated by the broken-line arrow is generated around the drive
electrode TL(n+2), and the magnetic field .PHI.I2 indicated by the
broken-line arrow is generated around the drive electrode TL(n+4).
The magnetic field .phi.I1 and the magnetic field .phi.I2 are
superimposed on each other in the area of the drive electrode
TL(n+3), thereby generating the strong magnetic field. In addition,
each of the drive electrodes TL(n), TL(n+1), TL(n+3) and TL(n+5),
except for the drive electrodes TL(n+2) and TL(n+4), is in the
floating state at this time.
[0257] As described above, it is possible to sequentially generate
the magnetic field from the side 2-U to the side 2-D as the
selection information SEI indicating the selection is shifted from
the unit drive circuits USL(n) and USR(n) to the unit drive circuit
USL(n+5), USR(n+5). In this case, it is possible to generate the
strong magnetic field, without forming the magnetic field
generation coil, by connecting the drive electrodes with each
other.
<<Operation of Electric Field Generation>>
[0258] In a case where the electric field touch detection is
instructed by the electric field enable signal TC_EN, the switch
control circuits SWL and SWR control the third switch and the fifth
switch when the selection signal supplied from the unit drive
circuit indicates selection so that the drive electrode
corresponding to the unit drive circuit which outputs the selection
signal indicating the selection is connected to the signal wiring
TSV. In order to generate an electric field, it is unnecessary to
cause a DC current to flow in the drive electrode differently from
the time of magnetic field generation, and thus the switch control
circuits SWL and SWR turn the fourth switch and the sixth switch
into the off-state.
[0259] FIG. 18 is a schematic plan view illustrating the operation
in the case where the electric field touch detection is designated.
FIG. 18 illustrates a state where the unit drive circuits USL(n+2)
and USR(n+2) output the selection signal indicating the
selection.
[0260] When the selection signal indicating the selection is
supplied from the unit drive circuit USL(n+2), the switch control
circuit SWL turns the third switch STLn+2, which is connected
between one end portion of the drive electrode TL(n+2)
corresponding to the unit drive circuit USL(n+2) and the signal
wiring TSV, into the on-state using the first drive signal. In
addition, the switch control circuit SWL performs control using the
first drive signal so that the other third switches STLn to STLn+1
and STLn+3 to STLn+5, except for the third switch STLn+2, are
turned into the off-state at this time.
[0261] When the selection signal indicating the selection is
supplied from the unit drive circuit USR(n+2), the switch control
circuit SWR turns the fifth switch STRn+2, which is connected
between the other end portion of the drive electrode TL(n+2)
corresponding to the unit drive circuit USR(n+2) and the signal
wiring TSV, into the on-state using the third drive signal. In
addition, the switch control circuit SWR performs control using the
third drive signal so that the other fifth switches STRn to STRn+1
and STRn+3 to STRn+5, except for the fifth switch STRn+2, are
turned into the off-state at this time.
[0262] The switch control circuits SWL and SWR turn the fourth
switch and the sixth switch, except for the fourth switch SVLn+2
and the sixth switch SVRn+2 connected to the drive electrode
TL(n+2) that generates the electric field, into the on-state using
the second drive signal and the fourth drive signal.
[0263] The drive signal TSVCOM with the periodically changing
voltage is supplied to the signal wiring TSV even at the time of
the electric field touch detection. Thus, the drive signal TSVCOM
is supplied to the one end portion of the drive electrode TL(n+2)
via the third switch STLn+2, and the drive signal TSVCOM is
supplied to the other end portion of the drive electrode TL(n+2)
via the fifth switch STRn+2. As a result, the drive signal TSVCOM
is supplied to the drive electrode TL(n+2) from both the end
portions thereof, and accordingly the electric field according to
the drive signal TSVCOM is generated around the drive electrode
TL(n+2).
[0264] The selection information SEI indicating the selection is
shifted from the unit drive circuits USL(n+2) and USR(n+2) to the
unit drive circuits USL(n+3) and USR(n+3) as a clock signal CLK
changes. Accordingly, the switch control circuit SWL turns the
third switch STLn+3 into the on-state, and the switch control
circuit SWR turns the fifth switch STRn+3 into the on-state. At
this time, the third switch except for the third switch STLn+3 and
the fifth switch except for the fifth switch STRn+3 are turned into
the off-state. Accordingly, the electric field according to the
drive signal TSVCOM is generated around the drive electrode TL(n+3)
arranged next to the drive electrode TL(n+2).
[0265] In the above-described manner, the electric field is
sequentially generated from the drive electrode arranged on the
side 2-U side to the drive electrode arranged on the side 2-D side
by changing the clock signal CLK.
[0266] Although FIGS. 15A to 18 illustrate the example where each
one of the third switch, the fourth switch, the fifth switch, and
the sixth switch is connected to one drive electrode, the invention
is not limited thereto. As illustrated in FIG. 13, for example,
each one of the third switch, the fourth switch, the fifth switch,
and the sixth switch may be connected to the six (plural) drive
electrodes arranged to be adjacent to each other.
[0267] In addition, the third switch, the fourth switch, the fifth
switch, and the sixth switch, which are connected to each of the
drive electrodes adjacent to each other, may be subjected to the
switch control substantially at the same time based on the
selection information sent from the same unit drive circuit. In
FIG. 16, for example, the third switch STLn connected to the drive
electrode TL(n) and the third switch STLn+1 connected to the drive
electrode TL(n+1) may be turned into the on-state substantially at
the same time based on the selection signal sent from the unit
drive circuit USL(n+2), and the sixth switch SVRn connected to the
drive electrode TL(n) and the sixth switch SVRn+1 connected to the
drive electrode TL(n+1) may be turned into the on-state
substantially at the same time based on the selection signal sent
from the unit drive circuit USR(n+2). Accordingly, it is possible
to generate the magnetic field by collectively using the drive
electrode TL(n) and the drive electrode TL(n+1) and to strengthen
the magnetic field thus generated.
[0268] When the drive electrode TL(n) and the drive electrode
TL(n+1) are collectively used, it is possible to further strengthen
the magnetic field generated in the area of the drive electrode
TL(n+2) by collectively using the drive electrode TL(n+3) and the
drive electrode TL(n+4) in the same manner. In this case, the
configuration where the drive electrode TL(n+3) and the drive
electrode TL(n+4) are collectively used is the same as the
configuration where the drive electrode TL(n) and the drive
electrode TL(n+1) are collectively used.
[0269] For example, it is possible to reduce the number of switches
in the configuration of the first embodiment as compared to the
configuration illustrated in FIGS. 36 and 37. Thus, the control
becomes easy, and it is possible to suppress the increase of the
occupied area.
<Configuration of Switching Regulator Circuit>
[0270] FIG. 19 is a plan view illustrating the configuration of the
display device 1 according to the first embodiment. FIG. 19
illustrates a state at the time of magnetic field touch detection.
As described with reference to FIGS. 14 to 17, the magnetic field
is generated using the drive electrode in the magnetic field
generation period TGT at the time of magnetic field touch
detection. As described with reference to FIGS. 1 to 2B, the
electric charge amount to be charged in the capacitive element C
inside the pen is changed by the magnetic field generated in the
magnetic field generation period TGT depending on whether the pen
is proximate. In the magnetic field detection period TDT, the
magnetic field generated by the coil L1 inside the pen is detected
based on the electric charge amount stored in the capacitive
element C inside the pen.
[0271] The description has been given in FIGS. 1 to 2B by
exemplifying the case where the magnetic field generation coil and
the magnetic field detection coil are configured using the same
coil. On the contrary, the magnetic field is generated without
using the coil (magnetic field generation coil) and the magnetic
field from the pen is detected by the magnetic field detection coil
in the magnetic field generation period TGT in the first embodiment
as described in FIGS. 14 to 17.
[0272] In the first embodiment, the magnetic field detection coil
is formed using the signal line in the magnetic field detection
period TDT.
[0273] FIG. 19 does not illustrate the drive electrode used for the
magnetic field generation in the magnetic field generation period
TGT, but illustrates only the signal line forming the magnetic
field detection coil in the magnetic field detection period TDT.
The signal line is used to detect the magnetic field in the
magnetic field detection period TDT, and thus can be regarded as
the detection electrode. When it is regarded in this manner, only
the detection electrode can be regarded as being drawn in FIG.
19.
[0274] In FIG. 19, the coil L1 inside the pen generates the
magnetic field based on electric charges of the capacitive element
C which is charged by the voltage induced by the magnetic field in
the magnetic field generation period TGT. In FIG. 19, numerals
SL(0) to SL(p) represent the signal lines. The signal lines SL(0)
to SL(p) cross the drive electrodes TL(0) to TL(p) as illustrated
in FIG. 10. That is, the signal lines SL(0) to SL(p) are arranged
in parallel to each other between the side 2-R and the side 2-L of
the display panel 2.
[0275] Although not particularly limited, a signal line SL(dL) for
magnetic field is arranged along the side 2-L of the display panel
2, and a signal line SL(dR) for magnetic field is arranged along
the side 2-R of the display panel 2 in the first embodiment. That
is, provided are the magnetic field signal line SL(dR) (second
signal line) arranged to be parallel to the signal lines SL(0) to
SL(p) (first signal line) along the side 2-R outside the active
area of the display panel 2, and the magnetic field signal line
SL(dL) (second signal line) arranged to be parallel to the signal
lines SL(0) to SL(p) along the side 2-R outside the active area of
the display panel 2. The magnetic field signal lines SL(dR) and
SL(dL) are provided outside the active area of the display panel 2,
and thus are used at the time of magnetic field touch detection
without affecting the display.
[0276] In the first embodiment, the switching regulator circuit SCX
is arranged along the side 2-U of the display panel 2. In FIG. 19,
the upper side indicates the side 2-U of the display panel 2 side,
and the lower side indicates the side 2-D of the display panel 2
side. The switching regulator circuit SCX is provided with seventh
switches j00 and j01 and eighth switches k00 to kp.
[0277] The signal lines SL(0) to SL(p) are arranged from the side
2-L to the side 2-R of the display panel 2 in this order although
not particularly limited thereto. In the first embodiment, the
signal lines, which are arranged with two signal lines sandwiched
therebetween, are connected to each other by the eighth switches
k00 to kp in the magnetic field detection period TDT. When the
description is given by exemplifying FIG. 19, the eighth switch k00
is connected between an end portion of the signal line SL(1) and an
end portion of the signal line SL(4), and the eighth switch k01 is
connected between an end portion of the signal line SL(3) and an
end portion of the signal line SL(6). In addition, the eighth
switch kn-1 is connected between an end portion of the signal line
SL(n-2) and an end portion of the signal line SL(n+1); the eighth
switch kn is connected between an end portion of the signal line
SL(n) and an end portion of the signal line SL(n+3); and the eighth
switch kn+1 is connected between an end portion of the signal line
SL(n+2) and an end portion of the signal line SL(n+5).
[0278] Further, the eighth switch kp-1 is connected between an end
portion of the signal line SL(p-6) and an end portion of the signal
line SL(p-3), and the eighth switch kp is connected between an end
portion of the signal line SL(p-4) and an end portion of the signal
line SL(p-1).
[0279] The seventh switch j00 is connected between an end portion
of the magnetic field signal line SL(dL) and an end portion of the
signal line SL(2), and the seventh switch j01 is connected between
an end portion of the magnetic field signal line SL(dR) and an end
portion of the signal line SL(p-2).
[0280] Each of the seventh switches j00 and j01 and the eighth
switches k00 to kp is subjected to the switch control by the
magnetic field enable signal SC_EN. In the first embodiment, the
seventh switches j00 and j01 and the eighth switches k00 to kp are
turned into the on-state when the magnetic field enable signal
SC_EN designates the magnetic field touch detection, and turned
into the off-state in the other cases.
[0281] As a result, the signal lines with the two signal lines
sandwiched therebetween are electrically connected to each other at
the time of magnetic field touch detection. When the description is
given by exemplifying FIG. 19, the signal lines SL(1) and SL(4),
which are arranged with the signal lines SL(2) and SL(3) sandwiched
therebetween, are electrically connected to each other via the
eighth switch k00. In the same manner, the signal line SL(3) and
the signal line SL(6), which are arranged with the signal lines
SL(4) and SL(5) sandwiched therebetween, are connected to each
other via the eighth switch k01; the signal line SL(n-2) and the
signal line SL(n+1), which are arranged with the signal lines
SL(n-1) and SL(n) sandwiched therebetween, are connected to each
other via the eighth switch kn-1; the signal line SL(n) and the
signal line SL(n+3), which are arranged with the signal lines
SL(n+1) and SL(n+2) sandwiched therebetween, are connected to each
other via the eighth switch kn; and the signal line SL(n+2) and the
signal line SL(n+5), which are arranged with the signal lines
SL(n+3) and SL(n+4) sandwiched therebetween, are connected to each
other via the eighth switch kn+1.
[0282] Further, the signal line SL(p-6) and the signal line
SL(p-3), which are arranged with the signal lines SL(p-5) and
SL(p-4) sandwiched therebetween, are connected to each other via
the eighth switch kp-1; and the signal line SL(p-4) and the signal
line SL(p-2), which are arranged with the signal lines SL(p-3) and
SL(p-2) sandwiched therebetween, are connected to each other via
the eighth switch kp.
[0283] Further, the magnetic field signal line SL(dL) and the
signal line SL(2), which are arranged with the signal lines SL(0)
and SL(1) sandwiched therebetween, are connected to each other via
the seventh switch j00; and the magnetic field signal line SL(dR)
and the signal line SL(p-2), which are arranged with the signal
lines SL(p-1) and SL(p) sandwiched therebetween, are connected to
each other via the seventh switch j01 in the first embodiment.
[0284] Accordingly, the magnetic field detection coil is formed
using a plurality of arbitrary signal lines among the signal lines
SL(0) to SL(p) in the magnetic field detection period TDT. In the
first embodiment, it is also possible to form the magnetic field
detection coil in the vicinity of the sides 2-R and 2-L of the
display panel 2 in the magnetic field detection period TDT. That
is, it is possible to form the magnetic field detection coil, which
inside has the signal lines SL(0) and SL(1) arranged to be
proximate to the side 2-L of the display panel 2, using the
magnetic field signal line SL(dL) and the signal line SL(2) as a
winding. Similarly, it is possible to form the magnetic field
detection coil, which inside has the signal lines SL(p-1) and SL(p)
arranged to be proximate to the side 2-R of the display panel 2,
using the magnetic field signal line SL(dR) and the signal line
SL(p-2) as a winding. Accordingly, it is also possible to detect a
case where the pen is proximate to the vicinity of the side 2-R and
the side 2-L. In addition, the magnetic field detection coils to be
formed overlap each other in the first embodiment as understood
from FIG. 19. Accordingly, it is possible to prevent a miss in
detection.
[0285] Widths d8 and d10 of the magnetic field signal lines SL(dR)
and SL(dL) are narrower than widths d9 and d10 of the signal lines
SL(0) to SL(p). Accordingly, it is possible to suppress the
increase of the frame.
[0286] In the magnetic field detection period TDT, the ground
voltage Vss is supplied to one terminal out of a pair of terminals
of each of the magnetic field detection coils formed by the signal
lines, and the other terminal is connected to the amplifier circuit
AMP described in FIG. 8. When the description is given by
exemplifying FIG. 19, the end portion of each of the signal lines
SL(n-2), SL(n) and SL(n+2) is connected to the amplifier circuit
AMP. When the magnetic field from the pen reaches the magnetic
field detection coil configured by the signal lines, the induced
voltage is generated in the magnetic field detection coil, and an
input signal of the amplifier circuit AMP is changed. The amplifier
circuit AMP amplifies this change of the input signal, and outputs
the amplified signal as the sense signals S(0) to S(p).
[0287] Meanwhile, the seventh switches j00 and j01 and the eighth
switches k00 to kp are turned into the off-state at the time of
electric field touch detection. At the time of electric field touch
detection, the drive electrode generates the electric field as
described with reference to FIGS. 14 and 18. The electric field
around the signal line is changed depending on whether the finger
is touched, and this change is sent to the amplifier circuit AMP,
and amplified and outputted as the sense signals S(0) to S(p).
[0288] The first embodiment has shown the example where the
magnetic field signal lines SL(dR) and SL(dL), which serve as the
winding at the time of forming the magnetic field detection coil,
are provided along the both sides of the display panel 2, but the
magnetic field signal lines SL(dR) and SL(dL) may be provided on
any one side, of course.
[0289] FIG. 20 is a perspective view schematically illustrating the
configuration of the display device 1 according to the first
embodiment. FIG. 20 illustrates the drive electrodes TL(0) to
TL(p), the signal lines SL(0) to SL(p), the eighth switches k00 to
kp, the drive semiconductor device DDIC, the selection drive
circuits SSR and SSL, and the gate driver 5. These parts are formed
on the TFT glass substrate TGB. Thus, FIG. 20 can be also regarded
as illustrating the display device 1 mounted to the module. In
addition, FIG. 20 also illustrates the pen provided with the coil
L1.
[0290] The selection drive circuit SSR is arranged along the side
900-R of the module, and the selection drive circuit SSL and the
gate driver 5 are arranged along the side 900-L. The signal lines
SL(0) to SL(p) are arranged to be parallel to each other between
the selection drive circuit SSL and the selection drive circuit
SSR, and the eighth switches k00 to kp are arranged along the side
900-U of the module. The drive electrodes TL(0) to TL(p) are
orthogonal to the signal lines SL(0) to SL(p), and arranged to be
parallel to each other.
[0291] The eighth switches k00 to kp connect the signal lines to
each other during the touch detection as described with reference
to FIG. 19. In FIG. 20, ninth switches l00 to lp formed on the TFT
glass substrate TGB are arranged along the side 900-D of the
module.
[0292] The ninth switches l00 to lp are divided into two groups,
the ninth switches of a first group being connected between an end
portion of each of the signal lines, to which the ground voltage
Vss needs to be supplied in the magnetic field detection period
TDT, for example, the signal lines SL(2), SL(n+3), SL(p-1) etc.
illustrated in FIG. 19, and a voltage wiring VL3, and being turned
into the on-state in the magnetic field detection period TDT. In
addition, the ninth switches of a second group are connected
between an end portion of the signal line, which outputs the change
of the signal in the coil in the magnetic field detection period
TDT, for example, the signal lines SL(1), SL(n), SL(p-4) etc.
illustrated in FIG. 19, and a corresponding signal wiring LL7. In
FIG. 20, reference signs l00, ln, ln+3 and lp are attached, for
example, to the ninth switch (second group) connected to the end
portion of the signal line SL(0); the ninth switch (second group)
connected to the end portion of the signal line SL(n); the ninth
switch (first group) connected to the end portion of the signal
line SL(n+3); and the ninth switch (first group) connected to the
end portion of the signal line L(p), respectively. The number of
signal wirings included in the signal wiring LL7 corresponds to the
number of the ninth switches of the second group although
illustrated as a single wiring. The ninth switches of the second
group are also turned into the on-state in the magnetic field
detection period. Accordingly, the signal generated in each of the
coils is transmitted to the corresponding signal wiring LL7,
amplified by the amplifier circuit AMP, and supplied to the touch
detection semiconductor device 6 (FIG. 8) as the sense signals S(0)
to S(p).
[0293] The ninth switches of the second group is also turned into
the on-state, the signal change in the signal line is supplied to
the amplifier circuit AMP, amplified, and supplied to the touch
detection semiconductor device 6 (FIG. 8) as the sense signals S(0)
to S(p) at the time of electric field touch detection.
[0294] In the first embodiment, the ninth switches l00 to lp are
formed on the TFT glass substrate, and the drive semiconductor
device DDIC is arranged to cover the ninth switches l00 to lp.
Accordingly, it is possible to suppress widening of the frame.
[0295] Although not particularly limited, the signal wiring TSV and
the voltage wiring VCOM extend along the side 900-R and 900-L of
the module. The drive signal TSVCOM is supplied to the signal
wiring TSV, and the ground voltage Vss is supplied to the voltage
wiring VCOM in the magnetic field generation period TGT. In
addition, the drive signal TSVCOM is supplied to the signal wiring
TSV at the time of electric field touch detection.
[0296] The selection drive circuits SSL and SSR cause the current
I1 in the direction indicated by the arrow to flow in the drive
electrodes TL(n-1) and TL(n) in the magnetic field generation
period TGT for the magnetic field touch detection. In addition, the
selection drive circuits SSL and SSR cause the current I2 in the
direction indicated by the arrow to flow in the drive electrodes
TL(n+3) and TL(n+4) at this time. Accordingly, the drive signal
TSVCOM periodically changes, and so the periodically changing
magnetic field is generated around each of the drive electrodes
TL(n-1), TL(n), TL(n+3) and TL(n+4). In FIG. 20, each state of the
generated magnetic fields .PHI.I1 and .PHI.I2 is schematically
illustrated in the broken line. The magnetic fields .PHI.I1 and
.PHI.I2 are superimposed on each other in an area of the drive
electrodes TL(n-1) and TL(n+1) sandwiched among the drive
electrodes TL(n-1), TL(n), TL(n+3) and TL(n+4), thereby generating
a strong magnetic field.
[0297] When the pen is present in the vicinity of the area where
the strong magnetic field is generated, the coil L1 inside the pen
generates the induced voltage due to the action of mutual
induction. The capacitive element C (not illustrated) inside the
pen PN is charged by the generated induced voltage.
[0298] The coil L1 inside the pen generates the magnetic field by
the electric charges charged in the capacitive element C in the
magnetic field detection period TDT. Magnetic lines at this time
are represented by .PHI.D in FIG. 20.
[0299] As described with reference to FIG. 19, the eighth switches
k00 to kp are turned into the on-state in the magnetic field
detection period TDT. Accordingly, the plurality of coils are
formed using the signal lines SL(0) to SL(p) as each winding. The
induced voltage is generated in the coil using the signal line as
the winding due to the action of mutual induction between the coil
using the signal line as the winding and the pen-in coil L1, and
the signal in the signal line is transmitted to the ninth switches
of the second group. When the ninth switches of the second group
are turned into the on-state, the signal is outputted from the
amplifier circuit AMP as the sense signals S(0) to S(p). In FIG.
20, the signal transmitted to the ninth switch ln via the signal
line SL(n) is indicated by the solid line with the arrow.
Accordingly, the coordinate touched by the pen can be specified by
specifying the detection electrode which detects the magnetic field
at the time of driving the drive electrode which has generated the
magnetic field.
[0300] Although the description has been given regarding the
example where the magnetic field signal lines SL(dL) and SL(dR) are
arranged outside the active area of the display panel 2, the
invention is not limited thereto. For example, the magnetic field
signal line SL(dL) and/or the magnetic field signal line SL(dR) may
be arranged along each of the sides 2-L and 2-R inside the active
area of the display panel 2. In this case, it is possible to reduce
narrowing of the display area by setting the width d10 of the
magnetic field signal wiring SL(dL) and/or SL(dR) to be arranged to
be narrower than a width d11 of the signal line.
Modified Example
[0301] FIG. 21 is a perspective view schematically illustrating a
configuration of the display device 1 according to a modified
example of the first embodiment. Since FIG. 21 is similar to FIG.
20, a different point from FIG. 20 will be mainly described. In the
display device 1 illustrated in FIG. 20, the magnetic field
detection coil has been formed using the signal lines SL(0) to
SL(p) at the time of magnetic field touch detection. In addition,
the change in the electric field has been also detected using the
signal lines SL(0) to SL(p) at the time of electric field touch
detection. In regard to this, detection electrodes RL(0) to RL(p)
formed on the CF glass substrate CGB are used to form a magnetic
field detection coil at the time of magnetic field touch detection
in the modified example. In addition, the detection electrodes
RL(0) to RL(p) are also used to detect a change in an electric
field at the time of electric field touch detection. That is, the
detection electrodes RL(0) to RL(p) formed on the CF glass
substrate CGB are used at each time of magnetic field touch
detection and electric field touch detection instead of the signal
lines SL(0) to SL(p) illustrated in FIG. 20.
[0302] The detection electrodes RL(0) to RL(p) are formed on the
main surface CSF1 of the CF glass substrate CGB as illustrated in
FIGS. 4A and 4B. Thus, the detection electrodes RL(0) to RL(p) are
formed on the drive electrodes TL(0) to TL(p) with the liquid
crystal layer, the color filter, and the CF glass substrate CGB
sandwiched therebetween. When seen in a plan view from the main
surface CSF1 of the CF glass substrate CGB side, the detection
electrodes RL(0) to RL(p) are parallel to each other and are
arranged to orthogonal to the drive electrodes TL(0) to TL(p).
[0303] In FIG. 21, one end portions the detection electrodes RL(0)
to RL(p) are connected to each other with a predetermined interval.
In the modified example, the one end portions of the detection
electrodes RL(0) to RL(p) are connected to each other with an
interval that causes two detection electrodes to be sandwiched
therebetween, similarly to the signal lines SL(0) to SL(p)
illustrated in FIG. 20. This connection is achieved by connecting
the detection electrodes using the signal wiring formed on the CF
glass substrate CGB. In FIG. 21, reference signs are attached only
to the detection electrodes RL(0) to RL(6), RL(n), RL(n+3) and
RL(p-3) to RL(p) among the detection electrodes RL(0) to RL(p) in
order to facilitate the viewability of the drawing. When the
description is given by exemplifying FIG. 21, the one end portions
of the detection electrodes RL(1) and RL(4) are connected to each
other on the side 900-U of the module side. In addition, the one
end portions of the detection electrode RL(3) and RL(6) are
connected to each other. Incidentally, the one end portion of the
detection electrode RL(2) is connected to the one end portion of
the detection electrode RL(0), which is the most proximate to the
side 900-L of the module with the single detection electrode TL(1)
sandwiched therebetween. One end portions of the other detection
electrodes are also connected to each other so as to sandwich two
detection electrodes except for the detection electrode
RL(p-3).
[0304] The respective other end portions of the detection
electrodes RL(0) to RL(p) are connected to the ninth switches l00
to lp formed on the TFT glass substrate TGB. In FIG. 21, the ninth
switches l00 to lp are drawn on the CF glass substrate CGB to
illustrate each connection between the detection electrodes RL(0)
to RL(p) and the ninth switches l00 to lp, but the ninth switches
l00 to lp are formed on the TFT glass substrate TGB similarly to
FIG. 20. Further, the ninth switches l00 to lp are covered by the
drive semiconductor device DDIC, similarly to the illustration in
FIG. 20. In FIG. 21, the drive semiconductor device DDIC is
indicated by the broken line on the TFT glass substrate TGB.
[0305] The ninth switches l00 to lp illustrated in FIG. 21 are
configured by a first group and a second group, similarly to the
ninth switches l00 to lp illustrated in FIG. 20. In the magnetic
field detection period TDT, the ground voltage Vss is supplied to
an end portion of the magnetic field detection coil formed using
the detection electrodes RL(0) to RL(p) as the ninth switches of
the first group are turned into the on-state, and the end portion
of the magnetic field detection coil is connected to the amplifier
circuit AMP as the ninth switches of the second group are turned
into the on-state.
[0306] In the modified example, the magnetic field is also
generated by the drive electrodes TL(0) to TL(p) in the magnetic
field generation period TGT similarly to FIG. 20. When the pen
generates the magnetic field .PHI.D based on the generated magnetic
field in the magnetic field detection period TDT, the magnetic
field .PHI.D is detected by the magnetic field detection coil
formed using the detection electrodes RL(0) to RL(p) and outputted
from the amplifier circuit AMP as the sense signals S(0) to S(p).
Thus, the coordinate touched by the pen can be specified by
specifying the detection electrode which is detected the magnetic
field at the time of driving the drive electrode which is generated
the magnetic field.
[0307] Similarly to FIG. 20, an electric field is generated by the
drive electrodes TL(0) to TL(p) at the time of electric field touch
detection, and a change in the electric field caused depending on
whether the finger is touched is transmitted to the amplifier
circuit AMP by the detection electrodes RL(0) to RL(p) and is
outputted as the sense signals S(0) to S(p).
[0308] The signal lines SL(0) to SL(p) are used to transmit the
image information in the display period, and thus need to be
electrically isolated from each other in the display period. Thus,
the seventh switch and the eighth switch are provided in the
display device 1 illustrated in FIGS. 19 and 20. In regard to this,
the magnetic field touch detection and the electric field touch
detection are performed using the detection electrodes RL(0) to
RL(p) without using the signal lines SL(0) to SL(p) in the modified
example illustrated in FIG. 21. Thus, it is unnecessary to provide
the seventh switch and the eighth switch for the magnetic field
touch detection, and it is possible to suppress the increase of the
occupied area.
[0309] Since it is not required to form the magnetic field
generation coil in the first embodiment, the control becomes easy,
and it is possible to suppress the increase of the occupied area of
the control circuit.
Second Embodiment
[0310] FIG. 22 is a plan view illustrating a configuration of the
display device 1 according to a second embodiment. FIG. 22
illustrates only a part relating to the display panel 2 described
in the first embodiment, and does not illustrate the other
parts.
[0311] In FIG. 22, numerals TL(0) to TL(p) represent drive
electrodes arranged in parallel to each other between the side 2-U
and the side 2-D of the display panel 2. In addition, numeral
TL(dLU) represents a dummy drive electrode for magnetic field
generation, which is arranged along the side 2-U in an area
(non-active area) outside the display panel 2, and numeral TL(dLD)
represents a dummy drive electrode for magnetic field generation
which is arranged along the side 2-D in the area (non-active area)
outside the display panel 2. The dummy drive electrodes for
magnetic field generation are arranged in the external area of the
display panel 2, and thus will be referred to also as an external
area drive electrode, hereinafter.
[0312] In addition, each of numerals USL(0) to USL(p) and USR(0) to
USR(p) represents a unit drive circuit in FIG. 22. As described
with reference to FIGS. 14, 16 and 17, the respective unit drive
circuits USL(0) to USL(p) are arranged along the side 2-L of the
display panel 2, and correspond to the drive electrodes TL(0) to
TL(p). In addition, the respective unit drive circuits USR(0) to
USR(p) are arranged along the side 2-R of the display panel 2, and
correspond to the drive electrodes TL(0) to TL(p).
[0313] As described in the first embodiment, the drive signal
TSVCOM is supplied to two drive electrodes, arranged to sandwich a
drive electrode corresponding to a unit drive circuit which outputs
a selection signal designating selection, in the magnetic field
generation period TGT. For example, when the unit drive circuits
USL(2) and USR(2) output the selection signal designating selection
in the magnetic field generation period TGT, the drive signal
TSVCOM is supplied to the drive electrodes TL(1) and TL(3) which
are arranged to sandwich the drive electrode TL(2) corresponding to
the unit drive circuits USL(2) and USR(2). That is, the drive
signal TSVCOM is supplied to one end portion of the drive electrode
TL(1) from the side 2-L side, and the ground voltage Vss is
supplied to the other end portion of the drive electrode TL(1) from
the side 2-R side. At this time, the drive signal TSVCOM is
supplied to the other end portion of the drive electrode TL(3) from
the side 2-R side, and the ground voltage Vss is supplied to one
end portion of the drive electrode TL(3) from the side 2-L side.
Accordingly, the magnetic field generated around the drive
electrode TL(1) and the magnetic field generated around the drive
electrode TL(3) are superimposed on each other around the drive
electrode TL(2) to be selected, thereby generating a strong
magnetic field.
[0314] In this case, a drive electrode proximate to the drive
electrode TL(0) is only the drive electrode TL(1) when the drive
electrode TL(0) arranged to be proximate to the side 2-U of the
display panel 2 is selected. Thus, the magnetic field generated
around the drive electrode TL(0) becomes weak when the drive
electrode TL(0) is selected. Similarly, a drive electrode proximate
to the drive electrode TL(p) is only the drive electrode TL(p-1)
when the drive electrode TL(p) arranged to be proximate to the side
2-D of the display panel 2 is selected. Thus, the magnetic field
generated around the drive electrode TL(p) becomes weak when the
drive electrode TL(p) is selected.
[0315] In the second embodiment, the external area drive electrode
TL(dLU) is arranged at the opposite side to the drive electrode
TL(0) with the side 2-U sandwiched therebetween, and the external
area drive electrode TL(dLD) is arranged at the opposite side to
the drive electrode TL(p) with the side 2-D sandwiched
therebetween.
[0316] When the drive electrode TL(0) is caused to generate the
magnetic field, each of the drive electrode TL(1) and the external
area drive electrode TL(dLU) arranged with the drive electrode
TL(0) sandwiched therebetween is caused to generate the magnetic
field. In addition, when the drive electrode TL(p) is caused to
generate the magnetic field, each of the drive electrode TL(p-1)
and the external area drive electrode TL(dLD) arranged with the
drive electrode TL(p) sandwiched therebetween is caused to generate
the magnetic field. Accordingly, it is possible to prevent
reduction in accuracy of detection of the pen in an area closer to
the sides 2-U and 2-D of the display panel 2.
[0317] Incidentally, the external area drive electrodes TL(dLU) and
TL(dLD) are used only for the magnetic field generation, and thus
each of line widths dLU and dLD may be narrower than each line
width dd of the drive electrodes TL(0) to TL(p).
[0318] FIG. 23 is a plan view illustrating the case of generating
the magnetic field around the drive electrode TL(0). The selection
circuit SL-C(FIGS. 8 and 14) is configured so that the drive signal
TSVCOM is supplied to one end portion of the external area drive
electrode TL(dLU) on the side 2-L side in response to the selection
signal from the unit drive circuit USL(0), and that the ground
voltage Vss is supplied to the one end portion of the drive
electrode TL(1) on the side 2-L side when the unit drive circuits
USL(0) and USR(0) corresponding to the drive electrode TL(0) output
the selection signal indicating the selection in the magnetic field
generation period TGT. In addition, the selection circuit
SR-C(FIGS. 8 and 14) is configured so that the ground voltage Vss
is supplied to the other end portion of the external area drive
electrode TL(dLU) on the side 2-R side in response to the selection
signal from the unit drive circuit USR(0) at this time, and that
the drive signal TSVCOM is supplied to the other end portion of the
drive electrode TL(1) on the side 2-R side.
[0319] Accordingly, when the drive electrode TL(0) arranged to be
the most proximate to the side 2-U is selected, the current I2 with
the arrow flows in the drive electrode TL(1), thereby generating
the magnetic field. In addition, the current I1 with the arrow
flows in the external area drive electrode TL(dLU), thereby
generating the magnetic field. The magnetic field generated by the
drive electrode TL(1) and the magnetic field generated by the
external area drive electrode TL(dLU) are superimposed on each
other in an area of the drive electrode TL(0), and so it is
possible to generate a strong magnetic field in the area of the
drive electrode TL(0).
[0320] FIG. 24 is a plan view illustrating the case of generating
the magnetic field around the drive electrode TL(p). The selection
circuit SL-C(FIGS. 8 and 14) is configured so that the ground
voltage Vss is supplied to the one end portion of the external area
drive electrode TL(dLU) on the side 2-L side in response to the
selection signal from the unit drive circuit USL(p), and that the
drive signal TSVCOM is supplied to one end portion of the drive
electrode TL(p-1) on the side 2-L side when the unit drive circuits
USL(p) and USR(p) corresponding to the drive electrode TL(p) output
the selection signal indicating the selection in the magnetic field
generation period TGT. In addition, the selection circuit
SR-C(FIGS. 8 and 14) is configured so that the drive signal TSVCOM
is supplied to the other end portion of the external area drive
electrode TL(dLU) on the side 2-R side in response to the selection
signal from the unit drive circuit USR(p) at this time, and that
the ground voltage Vss is supplied to the other end portion of the
drive electrode TL(p-1) on the side 2-R side.
[0321] Accordingly, when the drive electrode TL(p) arranged to be
the most proximate to the side 2-D is selected, the current I1 with
the arrow flows in the drive electrode TL(p-1), thereby generating
the magnetic field. In addition, the current I2 with the arrow
flows in the external area drive electrode TL(dLD), thereby
generating the magnetic field. The magnetic field generated by the
drive electrode TL(p-1) and the magnetic field generated by the
external area drive electrode TL(dLD) are superimposed on each
other in an area of the drive electrode TL(p), and so it is
possible to generate a strong magnetic field in the area of the
drive electrode TL(p).
[0322] The description has been given regarding the example where
the drive signal TSVCOM and the ground voltage Vss are supplied to
the two drive electrodes, which are arranged to sandwich the drive
electrode corresponding to the unit drive circuit that outputs the
selection signal indicating the selection, in the magnetic field
generation period TGT, but the invention is not limited thereto.
For example, two drive electrodes, which are arranged to sandwich a
drive electrode corresponding to an area where a strong magnetic
field is generated, may be selected by the corresponding unit
selection circuit. In this case, the unit drive circuits USL(dU)
and USR(dU) are arranged at both end portions of the external area
drive electrode TL(dLU), and the unit drive circuits USL(dD) and
USR(dD) are arranged at both end portions of the external area
drive electrode TL(dLD) as illustrated in FIGS. 22 to 24.
[0323] In this case, among the unit drive circuits USL(0) to
USL(p), USL(dL) and USL(dD), two unit drive circuits, which are
arranged to sandwich the unit drive circuit corresponding to the
drive electrode that generates the strong magnetic field, output
the selection signal indicating the selection in the magnetic field
generation period TGT. Similarly, among the unit drive circuits
USR(0) to USR(p), USR(dL) and USR(dD), two unit drive circuits,
which are arranged to sandwich the unit drive circuit corresponding
to the drive electrode that generates the strong magnetic field,
output the selection signal indicating the selection.
[0324] For example, when a strong magnetic field is caused to be
generated in an area of the drive electrode TL(2), the unit drive
circuit USL(1) and the unit drive circuit USL(3) arranged to
sandwich the unit selection circuit USL(2) output the selection
signal indicating the selection. The selection circuit SL-C(FIGS. 8
and 14) supplies the drive signal TSVCOM to the one end portion of
the drive electrode TL(1) corresponding to the unit selection
circuit USL(1) based on the selection signals from the unit
selection circuits USL(1) and USL(3), and supplies the ground
voltage Vss to the one end portion of the drive electrode TL(3)
corresponding to the unit selection circuit USL(3).
[0325] At this time, the unit drive circuit USR(1) and the unit
drive circuit USR(3), which are arranged to sandwich the unit
selection circuit USR(2) corresponding to the drive electrode
TL(2), output the selection signal indicating the selection. The
selection circuit SR-C(FIGS. 8 and 14) supplies the ground voltage
Vss to the other end portion of the drive electrode TL(1)
corresponding to the unit selection circuit USR(1) based on the
selection signals from the unit selection circuits USR(1) and
USR(3), and supplies the drive signal TSVCOM to the other end
portion of the drive electrode TL(3) corresponding to the unit
selection circuit USR(3). Accordingly, the magnetic field generated
around the drive electrode TL(1) and the magnetic field generated
around the drive electrode TL(3) are superimposed on each other in
the area of the drive electrode TL(2).
[0326] When the drive electrode TL(0) is caused to generate the
strong magnetic field, the unit drive circuits USL(dU), USR(dU),
USL(1) and USR(1) illustrated in FIG. 23 output the selection
signal indicating the selection. In response to this, the selection
circuit SL-C supplies the drive signal TSVCOM to the one end
portion of the external area drive electrode TL(dLU), and supplies
the ground voltage Vss to the one end portion of the drive
electrode TL(1). In addition, the selection circuit SR-C supplies
the ground voltage Vss to the other end portion of the external
area drive electrode TL(dLU), and supplies the drive signal TSVCOM
to the other end portion of the drive electrode TL(1). Accordingly,
the currents I1 and I2 indicated by the arrows in FIG. 23 flow, the
magnetic field is generated, and it is possible to generate the
strong magnetic field in the area of the drive electrode TL(0).
[0327] When the drive electrode TL(p) is caused to generate the
strong magnetic field, the unit drive circuits USL(dD), USR(dD),
USL(p-1) and USR(p-1) illustrated in FIG. 24 output the selection
signal indicating the selection. In response to this, the selection
circuit SL-C supplies the ground voltage Vss to the one end portion
of the external area drive electrode TL(dLD), and supplies the
drive signal TSVCOM to the one end portion of the drive electrode
TL(p-1). In addition, the selection circuit SR-C supplies the drive
signal TSVCOM to the other end portion of the external area drive
electrode TL(dLU), and supplies the ground voltage Vss to the other
end portion of the drive electrode TL(p-1). Accordingly, the
currents I1 and I2 indicated by the arrows in FIG. 24 flow, the
magnetic field is generated, and it is possible to generate the
strong magnetic field in the area of the drive electrode TL(p).
[0328] Of course, the external area drive electrode may be arranged
only on one side of the display panel 2.
[0329] In the second embodiment, it is possible to reduce an area
where the detection accuracy is decreased, within the area (the
area of the display panel 2) where the display is performed.
Third Embodiment
[0330] In the display device 1, display is performed in the display
panel 2, and detection on whether an external proximity object such
as a pen and a finger touches inside an area of the display panel 2
or the like is performed simultaneously. In a third embodiment, the
detection on whether the external proximity object touches inside
the area of the display panel 2 or the like is performed by
executing detection steps of a plurality of stages during one frame
period that performs the display in the display panel 2. Here, a
description will be given regarding an example where the touch of
the external proximity object is detected by executing the
detection steps of two stages during one frame period.
[0331] The detection steps of two stages include a detection step
at a first stage and a detection step at a second stage which is
executed after the detection step at the first stage. In the
detection step at the first stage, the detection on whether an
object, for example, the pen, which can be detected by magnetic
field touch detection as the external proximity object, touches the
area of the display panel 2 is roughly performed. When it is
detected that the pen as the external proximity object touches the
area of the display panel 2 in the detection step at the first
stage, the magnetic field touch detection to detect a coordinate, a
distance or the like of the touch is finely performed. On the other
hand, when the touch by the pen is not detected in the detection
step at the first stage, electric field touch detection is
performed. This finely performed magnetic field touch detection or
electric field touch detection becomes the detection step at the
second stage. Accordingly, if any of the pen and the finger touches
inside the area of the display panel 2, the touch can be detected
during the one frame period in which the display is being
performed.
[0332] The detection step at the second stage is realized by the
touch detection semiconductor device 6 (FIG. 8) and the drive
semiconductor device DDIC (FIG. 8) although not particularly
limited thereto. That is, the control circuit T-CNT inside the
touch detection semiconductor device 6 divides the one frame period
into a first period and a second period subsequent thereto, and
instructs the magnetic field touch detection using the magnetic
field enable signal SC_EN in the first period. In addition, the
selection drive circuits SSL and SSR are controlled using the
control signal Y-CNT in the first period so that the magnetic field
touch detection is roughly performed. In the first period, the
control circuit D-CNT inside the drive semiconductor device DDIC is
notified of whether the touch by the pen is detected by the control
signal SW sent from the touch detection semiconductor device 6. In
the first period, the selection drive circuits SSL and SSR are
controlled by the control signal Y-CNT so that the magnetic field
touch detection is roughly performed.
[0333] When the touch by the pen is detected during the magnetic
field touch detection in the detection step at the first stage, the
control circuit D-CNT inside the drive semiconductor device DDIC
instructs the magnetic field touch detection using the magnetic
field enable signal SC_EN even in the second period. In this case,
the selection drive circuits SSL and SSR are controlled by the
control signal Y-CNT in the second period so that the magnetic
field touch detection is finely performed. Accordingly, the
detection of touch by the pen is performed in the second
period.
[0334] On the other hand, when the touch by the pen is not detected
during the magnetic field touch detection in the detection step at
the first stage, the control circuit D-CNT inside the drive
semiconductor device DDIC instructs the electric field touch
detection using the electric field enable signal TC_EN in the
second period. Accordingly, the electric field touch detection is
performed, and the detection of touch by the finger is performed in
the second period.
[0335] Although the description has been given regarding the
example where the drive semiconductor device DDIC executes the
detection steps at the two stages based on the control signal SW
sent from the touch detection semiconductor device 6, the invention
is not limited thereto. For example, the touch detection
semiconductor device 6 may execute control of the detection steps
at the two stages so that the magnetic field enable signal SC_EN,
the electric field enable signal TC_EN, and the like are outputted
from the drive semiconductor device DDIC by the control signal
SW.
[0336] A difference between the rough magnetic field touch
detection and the fine magnetic field touch detection is a
difference in the number of drive electrodes sandwiched between
drive electrodes to which a drive signal is supplied in the
magnetic field generation period TGT. That is, the number of drive
electrodes sandwiched between the drive electrodes in the case of
the rough magnetic field touch detection is larger than that in the
case of the fine magnetic field touch detection in the magnetic
field generation period TGT. For example, in the case of the rough
magnetic field touch detection, the drive signal TSVCOM is supplied
to a pair of drive electrodes with 32 drive electrodes sandwiched
therebetween as described in the first and second embodiments. In
regard to this, in the case of the fine magnetic field touch
detection, the drive signal TSVCOM is supplied to a pair of drive
electrodes that sandwiches drive electrodes equal to or more than
one and smaller than 32 as described in the first and second
embodiments.
[0337] For example, when the number of drive electrodes to which
the drive signal TSVCOM is supplied is the same at the rough
magnetic field touch detection and the fine magnetic field touch
detection, it is possible to detect the touch by the pen in the
entire area of the display panel 2 for a short time by performing
the rough magnetic field touch detection. On the other hand, a
distance between the pair of drive electrodes to which the drive
signal is supplied becomes short in the case of the fine magnetic
field touch detection, and so it is possible to generate a strong
magnetic field and to achieve the improvement of the detection
accuracy. When the magnetic field touch detection is performed in
both of the first period and the second period, the first period
can be regarded as the rough magnetic field touch detection period,
and the second period can be regarded as the fine magnetic field
touch detection period.
[0338] In addition, the magnetic field to be generated may be
strengthened by increasing the number of drive electrodes to which
the drive signal is supplied during the rough touch detection. As
described with reference to FIG. 13B, for example, each of the pair
of drive electrodes to which the drive signal TSVCOM is supplied
may be provided as a bundle configured using a plurality of drive
electrodes.
[0339] When the touch by the pen is not detected in the first
period, the electric field touch detection is performed so that the
touch by the finger is detected in the second period. Thus, it is
also possible to detect the touch by the finger.
[0340] The detection of touch is performed with respect to the
entire area of the display panel 2 in each of the first period and
the second period. Thus, the entire area of the display panel 2 can
be regarded as being subjected to the touch detection twice during
one frame period. When being regarded in this manner, the touch
detection at the first time is the magnetic field touch detection
and the touch detection at the second time is the magnetic field
touch detection or the electric field touch detection.
[0341] FIGS. 25A to 25I are timing diagrams illustrating operations
of the display device 1 according to the third embodiment. In FIGS.
25A to 25I, the horizontal axis represents time t. FIG. 25A is the
timing diagram illustrating a frame signal F. The drive
semiconductor device DDIC performs display on the display panel 2
according to the frame signal F. That is, the drive semiconductor
device DDIC performs the display with respect to the entire area of
the display panel 2 during one period TF of the frame signal F. In
other words, the display for one screen is performed during one
frame period (TF).
[0342] FIG. 25B is the timing diagram illustrating the one period
(one frame period) TF of the periodical frame signal F. In FIG.
25B, numeral TF1 represents a first period which starts in response
to the frame signal F, and numeral TF2 represents a second period
which is subsequent to the first period TF1. When the display is
performed in the display device 1, the frame period TF illustrated
in FIG. 25B is repeated, and so the first period TF1 and the second
period TF2 are alternately generated in this order.
[0343] FIG. 25C is the timing diagram schematically illustrating
the display period and the touch detection period. In FIG. 25C,
each of periods DPS1 to DPSp filled with the oblique line
represents the display period. Incidentally, reference signs are
attached only to DPS1, DPS2, DPSn to DPSn+2 and DPSp regarding the
display period in FIG. 25C to prevent the drawing from being
complicated. In each of the display periods DPS1 to DPSp, the image
information is supplied from the drive semiconductor device DDIC to
the signal line, the scan line becomes a high level, and so the
image information is displayed on the display panel 2. As the
display is performed in each of the display periods DPS1 to DPSp,
the display for one screen is performed.
[0344] In FIG. 25C, numerals CSS11 to CSS1p and CSS21 to CSS2p
represent the touch detection periods. Here, numerals CSS11 to
CSS1p represent the touch detection periods executed in the first
period TF1, and numerals CSS21 to CSS2p represent the touch
detection periods executed in the second period TF2. The rough
magnetic field touch detection is performed in each of the touch
detection periods CSS11 to CSS1p, and the detection of touch by the
pen is performed with respect to the entire area of the display
panel 2 as the magnetic field touch detection is performed in each
of the touch detection periods CSS11 to CSS1p.
[0345] The fine magnetic field touch detection or the electric
field touch detection is performed in each of the touch detection
periods CSS21 to CSS2p. As the touch detection is performed in each
of the touch detection periods CSS21 to CSS2p, the detection of
touch by the pen or the finger is performed with respect to the
entire area of the display panel 2.
[0346] Since the rough magnetic field touch detection is performed
in each of the touch detection periods CSS11 to CSS1p, it is
possible to detect the touch with respect to the entire area of the
display panel 2 at a small number of times. Thus, the touch
detection on the entire area is completed at time tp before the
display for one screen is completed. Accordingly, the time to
perform the touch detection targeting the entire area of the
display panel 2 can be secured until the display for one screen is
completed. As a result, the touch detection on the entire area is
performed again in the touch detection periods CSS21 to CSS2p from
the time tp.
[0347] FIG. 25D to FIG. 25I are the timing diagrams illustrating
the drive signal TSVCOM which is supplied to the drive electrodes
TL(n) to TL(n+5) arranged on the display panel 2.
[0348] The drive signal is supplied to each of the drive signals
TL(n) to TL(n+5) from the selection drive circuits SSL and SSR
illustrated in FIG. 8. In FIG. 25D to FIG. 25I, each left side
illustrates the drive signal which is supplied to the drive
electrodes TL(n) to TL(n+5) in the touch detection period CSS12,
and each right side illustrates the drive signal which is supplied
to the drive electrodes TL(n) to TL(n+5) in the touch detection
period CSS24.
[0349] For example, the drive signal TSVCOM is supplied to one end
portion of the drive electrode TL(n) from the selection drive
circuit SSL, and the ground voltage Vss is supplied to one end
portion of the drive electrode TL(n+5) in the touch detection
period CSS12. At this time, the ground voltage Vss is supplied to
the other end portion of the drive electrode TL(n) from the
selection drive circuit SSR, and the drive signal TSVCOM is
supplied to the other end portion of the drive electrode TL(n+5).
Accordingly, the magnetic field is generated around each of the
drive electrode TL(n) and the drive electrode TL(n+5). The
generated magnetic fields are superimposed on each other in an area
of the drive electrodes TL(n+1) to TL(n+4) which are sandwiched
between the drive electrode TL(n) and the drive electrode
TL(n+5).
[0350] On the other hand, for example, the drive signal TSVCOM is
supplied to the one end portion of the drive electrode TL(n) from
the selection drive circuit SSL, and the ground voltage Vss is
supplied to one end portion of the drive electrode TL(n+2) in the
touch detection period CSS24. At this time, the ground voltage Vss
is supplied to the other end portion of the drive electrode TL(n)
from the selection drive circuit SSR, and the drive signal TSVCOM
is supplied to the other end portion of the drive electrode
TL(n+2). Accordingly, the magnetic field is generated around each
of the drive electrode TL(n) and the drive electrode TL(n+2). The
generated magnetic fields are superimposed on each other in an area
of the drive electrode TL(n+1) which is sandwiched between the
drive electrode TL(n) and the drive electrode TL(n+2). Since only
the drive electrode TL(n+1) is sandwiched between the drive
electrodes to which the drive signal TSVCOM is supplied, a distance
between the drive electrodes becomes short, and the magnetic field
obtained through the superimposition of the magnetic field becomes
strong. As a result, it is possible to achieve the improvement of
the detection accuracy.
[0351] In addition, the drive signal TSVCOM may be supplied to the
drive electrodes TL(n) and TL(n+1) from the selection drive circuit
SSL, and the drive signal TSVCOM may be supplied to the drive
electrodes TL(n+4) and TL(n+5) from the selection drive circuit SSR
in the touch detection period CSS12. That is, two (a plurality of)
drive electrodes may be used as a bundle to supply the drive signal
TSVCOM at the time of rough magnetic field touch detection.
Accordingly, it is possible to strengthen the magnetic field to be
generated and to achieve the improvement of the detection accuracy
even at the time of rough magnetic field touch detection.
[0352] Although the description has been given regarding the
example where the magnetic field touch detection is performed in
each of the touch detection periods CSS21 to CSS2p, the electric
field touch detection is performed in each of the touch detection
periods CSS21 to CSS2p when no touch by the pen is detected in the
first period TF1. Accordingly, it is possible to detect whether the
finger touches the entire area of the display panel 2 or the like
in the second period TF2
[0353] The switch between the rough magnetic field touch detection
and the fine magnetic field touch detection using the control
signal Y-CNT can be achieved by controlling the switch control
circuits SWL and SWR using a switching control signal based on the
control signal Y-CNT, for example. When the switching control
signal indicates the rough magnetic field touch detection, it is
possible to perform the rough magnetic field touch detection by
causing the switch control circuits SWL and SWR to supply the drive
signal TSVCOM and the ground voltage Vss to a pair of drive
electrodes arranged to sandwich a drive electrode corresponding to
a unit drive circuit, which outputs the selection signal indicating
selection, and a drive electrode next to this drive electrode.
[0354] In addition, when the unit drive circuits correspond to the
respective drive electrodes as illustrated in FIG. 22, it is
possible to achieve the switch between the rough magnetic field
touch detection and the fine magnetic field touch detection by
changing a timing to supply the selection information SEI
indicating the selection to a shift register configured by the unit
drive circuits.
<Magnetic Field Touch Detection Operation>
[0355] FIGS. 26A to 26F are timing diagrams illustrating each
relationship between the touch detection period and the display
period. As illustrated in FIGS. 25A to 25I, the touch detection
periods CSS11 to CSS1p, CSS21 to CSS2p and the display periods DPS1
to DPSp are alternately generated. In FIGS. 26A to 26F, exemplified
is a case where the display period is generated after the touch
detection period. In addition, the touch detection period is
indicated by reference sign CSS to collectively illustrate the
touch detection periods CSS11 to CSS1p, CSS21 to CSS2p, and the
display period is indicated by reference sign DPS to collectively
illustrate the display periods DPS1 to DPSp in FIGS. 26A to 26F.
Further, FIGS. 26A to 26F illustrate a case where the magnetic
field touch detection is performed in the touch detection period
CSS. Incidentally, the horizontal axis represents the time t also
in FIGS. 26A to 26F.
[0356] FIG. 26A is the schematic timing diagram illustrating the
configuration of the magnetic field touch detection which is
performed in the touch detection period CSS. The touch detection
period includes the magnetic field generation period TGT, the
magnetic field detection period TDT, and a precharge period RST. In
the precharge period RST, each voltage of the drive electrodes
TL(0) to TL(p), the signal lines SL(0) to SL(p), and the like is
precharged to a predetermined value in order for the display period
DPS to be subsequently generated.
[0357] As described above, the magnetic field generation period TGT
is the period to generate the magnetic field, and the magnetic
field detection period TDT is the period to detect the magnetic
field from the pen by the magnetic field detection coil. The
control circuit D-CNT illustrated in FIG. 8 changes the magnetic
field enable signal SC_EN from a high level to a low level in the
touch detection period CSS as illustrated in FIG. 26C. Accordingly,
the magnetic field touch detection is designated. In addition, the
control circuit D-CNT causes the drive signal TSVCOM to
periodically change in the magnetic field generation period TGT as
illustrated in FIG. 26B. Accordingly, as described above, the drive
signal TSVCOM is supplied to each of the pair of drive electrodes
arranged with the drive electrode sandwiched therebetween, the
magnetic field depending on the change of the drive signal TSVCOM
is generated, and the superimposition of the magnetic field is
performed in the area of the drive electrode sandwiched between the
pair of drive electrodes.
[0358] The capacitive element inside the pen is charged by the
magnetic field generated in the magnetic field generation period
TGT. When there is the touch of the pen, the magnetic field
generated by the pen is detected by the magnetic field detection
coil in the magnetic field detection period TDT, and the detection
signal depending on the detected magnetic field is outputted from
the magnetic field detection coil. In addition, the control circuit
D-CNT sets the drive signal TSVCOM to the predetermined voltage,
and sets the magnetic field enable signal SC_EN to the high level
as illustrated in FIG. 26B in the display period DPS.
[0359] Next, an example of the detection circuit to perform the
detection on whether the pen touches or not based on the detection
signal sent from the magnetic field detection coil will be
described with reference to FIG. 27. Although the detection circuit
to detect the touch is configured using the amplifier circuit AMP
and the touch semiconductor device 6 in FIG. 8, here, the detection
circuit using a microcontroller MCU will be exemplified.
[0360] FIGS. 26D to 26F are the timing diagrams for describing the
operation of the detection circuit illustrated in FIG. 27. Thus,
FIGS. 26D to 26F will be referred to while describing the
configuration and operation of the detection circuit illustrated in
FIG. 27.
[0361] In FIG. 27, numeral MPX represents a multiplexer (selector)
provided with a plurality of switches SWA0 to SWAp. As described in
the first embodiment, magnetic field detection coils CY(0) to CY(p)
are configured using the signal lines SL(0) to SL(p) or the
detection electrodes RL(0) to RL(p) in the magnetic field detection
period TDT. One end portion of each of the magnetic field detection
coils is connected to each one end portion of the corresponding
switches SWA0 to SWAp, and each of the other end portions thereof
is connected to the ground voltage Vss. As described in FIG. 19 and
the like, for example, the one end portion of the magnetic field
detection coil CY(0), which is formed by connecting two signal
lines arranged in parallel to each other, is connected to the one
end portion of the switch SWA0, and the other end portion thereof
is connected to the ground voltage Vss. The remaining magnetic
field detection coils CY(1) to CY(p) are also connected between the
one end portion of each of the corresponding switches SWA1 to SWAp
and the ground voltage Vss in the same manner.
[0362] In addition, the other end portion of each of the switches
SWA0 to SWAp is connected to a node nA. Any of the switches SWA0 to
SWAp is selected and turned into the on-state in the magnetic field
detection period TDT. This selection is performed by the
microcontroller MCU. That is, any of the switches SWA0 to SWAp is
selected and turned into the on-state by a selection signal sent
from the microcontroller MCU. FIG. 26D illustrates a waveform of a
selection signal SC_SEL which turns one of the switches SWA0 to
SWAp into the on-state. In FIG. 26D, the switch is turned into the
on-state as the selection signal SC_SEL is changed from the high
level to the low level.
[0363] When any of the switches SWA0 to SWAp is turned into the
on-state in the magnetic field detection period TDT, a detection
signal in the magnetic field detection coil is transmitted to the
node nA. A detection signal in the node nA is supplied to a gain
circuit, and amplified by the gain circuit. The amplified detection
signal is supplied to a filter circuit in order to remove noise,
and an output of the filter circuit is rectified by a rectifier
circuit, and is supplied to an integrating circuit. An output of
the integrating circuit is supplied to the microcontroller MCU.
[0364] Although not illustrated in Figure, the microcontroller MCU
includes an analog/digital conversion circuit, a clock signal
generation circuit, a non-volatile memory in which a program is
stored, and a processing unit that operates according to the
program stored in the non-volatile memory. The above-described
output from the integrating circuit is supplied to the
analog/digital conversion circuit via a terminal ADC of the
microcontroller MCU, and is converted into a digital signal. The
digital signal obtained through the conversion is processed by the
processing unit, and the determination is performed on whether the
pen is proximate to any one of the coils CY(0) to CY(p).
[0365] The processing unit inside the microcontroller MCU forms a
control signal according to the program. The control signal
includes the selection signal to select the switches SWA0 to SWAp,
an enable signal EN, and a reset signal rst. Further, the clock
signal MCLK with a periodically changing voltage is generated by
the clock signal generation circuit inside the microcontroller
MCU.
[0366] The clock signal MCLK is supplied to a buffer circuit BF.
The buffer circuit BF is controlled by the enable signal EN. When
the enable signal EN is a high level, the clock signal MCLK is
supplied to the node nA via a resistance R11. On the other hand, an
output of the buffer circuit BF is set to a high-impedance state
(Hi-Z) when the enable signal EN is a low level.
[0367] The gain circuit includes resistances R8 to R10, an
operational amplifier OP4, and a capacitive element CP3 for cut-off
of direct current. The detection signal is supplied to a positive
phase input (+) of the operational amplifier OP4, and an inverting
input (-) of the operational amplifier OP4 is connected to the
ground voltage Vss via the resistance R9, and is connected to an
output of the operational amplifier OP4 via the resistance R8.
[0368] The filter circuit includes resistances R4 to R7, a
capacitive element CP2, and an operational amplifier OP3. A
positive phase input (+) of the operational amplifier OP3 is
connected to the ground voltage Vss via the resistance R7, and an
output signal from the gain circuit is supplied via the capacitive
element CP2. In addition, an inverting input (-) of the operational
amplifier OP3 is supplied to the ground voltage Vss via the
resistance R6, and is connected to the output of the operational
amplifier via the resistance R5. Further, the output of the
operational amplifier OP3 is connected to an input of the filter
circuit via the resistance R4.
[0369] The rectifier circuit includes resistances R1 to R3, an
operational amplifier OP2, and a diode D. A positive phase input
(+) of the operational amplifier is connected to the ground voltage
Vss via the resistance R3, and an output from the filter circuit is
supplied to an inverting input (-) of the operational amplifier OP2
via the resistance R2. Further, the output of the rectifier circuit
is supplied via the resistance R1. An output of the operational
amplifier OP2 is outputted via the diode D.
[0370] The integrating circuit includes a capacitive element CP1, a
switch SWAA which receives the reset signal rst as the switch
control signal, and an operational amplifier OP1. A positive phase
input (+) of the operational amplifier is connected to the ground
voltage Vss, and an inverting input (-) is connected to the output
of the integrating circuit via the capacitive element CP1. Further,
the switch SWAA is connected between the output and input of the
integrating circuit.
[0371] In FIGS. 26A to 26F, the reset signal rst becomes the low
level at time t0. Accordingly, the switch SWAA is turned into the
off-state, and the reset is released. At this time, the
microcontroller MCU sets the enable signal EN to the high level.
Accordingly, the clock signal CLK is supplied from the buffer
circuit BF to the node nA via the resistance R11.
[0372] The clock signal CLK supplied to the node nA is also
supplied to the gain circuit. An output OUT1 of the gain circuit is
changed according to a voltage change of the clock signal MCLK, and
thus is changed as illustrated in FIG. 26E. The output OUT1 of the
gain circuit is supplied to the rectifier circuit via the filter
circuit, and the rectified output is supplied to the integrating
circuit. A voltage of the node nA is periodically changed from time
t0 to time t1, but is not changed in terms of an envelope curve,
and thus the output of the integrating circuit becomes a constant
value.
[0373] The microcontroller MCU sets the enable signal EN to the low
level at the time t1. Accordingly, the node nA is set to the
high-impedance state (Hi-Z). In addition, a switch SWA3
corresponding to the coil CY(3), for example, is turned into the
on-state by the selection signal SC_SEL (FIG. 26D) at the time t1.
Accordingly, one end portion of the coil CY(3) is in the state of
being connected to the node nA.
[0374] At this time, as the pen is present in the vicinity of the
coil CY(3), the induced voltage is generated in the coil inside the
pen by the magnetic field generated in the magnetic field
generation period TGT between the time t0 and t2, and the
capacitive element C (FIG. 2) is charged.
[0375] In the time t1, the coil L1 inside the pen generates the
magnetic field based on the electric charge amount charged in the
capacitive element C. The induced voltage is generated in the coil
CY(3) according to a change of the magnetic field generated by the
coil L1.
[0376] As a result, the output OUT1 of the gain circuit is
attenuated while oscillating as illustrated in FIG. 26E. That is,
the voltage is attenuated in terms of an envelope curve. Since the
output OUT1 of the gain circuit is attenuated while oscillating
from the time t1, the output OUT2 of the integrating circuit
gradually increases as illustrated in FIG. 26F. The microcontroller
MCU converts the output OUT2 of the integrating circuit into a
digital signal, and determines that the pen is present. At this
time, the microcontroller MCU grasps the switch turned into the
on-state among the switches SWA0 to SWAp using the selection signal
SC_SEL, and so is capable of grasping a position of the selected
magnetic field generation coil. Therefore, it is possible to
determine the position at which the pen is present, that is, the
touched position, the pen pressure of the pen, and the like from a
value of the digital signal obtained by the conversion and from the
grasped position of the magnetic field detection coil. It is
possible to determine the presence or absence of the pen, the
writing pressure, and the like by repeating the above-described
operations.
[0377] In the detection circuit illustrated in FIG. 27, the gain
circuit, the filter circuit, the rectifier circuit and the
integrating circuit can be shared among the plurality of magnetic
field detection coils CY(0) to CY(p), and it is possible to
suppress the increase of an area occupied by the detection
circuit.
Fourth Embodiment
[0378] FIG. 28 is a plan view illustrating a configuration of the
display device 1 according to a fourth embodiment. FIG. 28
illustrates the schematic plan view of the display panel 2.
[0379] In FIG. 28, numerals Tx1-1 to TxN-M represent drive
electrodes (detection electrodes) which are arranged in a dot
matrix form in the display panel 2. Whether there is touch by a
finger, for example, is detected as a change of an electric charge
amount by the drive electrodes arranged in the dot matrix form. In
FIG. 28, the drive electrodes arranged in five rows and five
columns are exemplified among the drive electrodes arranged in the
dot matrix form. In addition, numerals SDL(1) to SDL(m) represent
detection signal lines, and numerals GL(1) to GL(n) represent scan
lines. The detection signal lines SDL(1) to SDL(m) are arranged in
parallel to the signal lines SL(0) to SL(p) (not illustrated) in
the display panel 2. When the description is given with reference
to FIG. 10, for example, the signal lines SL(n-6) to SL(n+9) extend
in the column direction and are arranged in parallel in the row
direction, and the detection signal lines SDL(1) to SDL(m) extend
in the column direction and are arranged in parallel in the row
direction similarly to the signal lines SL(0) to SL(p).
[0380] The respective drive electrodes Tx1-1 to TxN-M arranged in
the dot matrix form are connected to the detection signal lines
SDL(1) to SDL(m) having one-to-one correspondence. For example, the
drive electrodes Tx1-1, Tx1-2, Tx1-3, Tx1-17 and Tx1-M, which are
arranged on the first row of the dot matrix, are connected to the
detection signal lines SDL(1), SDL(n+1), SDL(2n+1), SDL(+1) and
SDL(m-n) having one-to-one correspondence. In addition, the drive
electrodes TxN-1, TxN-2, TxN-3, TxN-17 and TxN-M, which are
arranged on the N-th row of the dot matrix, are connected to the
detection signal lines SDL(n), SDL(2n), SDL(3n), SDL(+n) and SDL(m)
having one-to-one correspondence.
[0381] In the fourth embodiment, detection of touch by the finger
is performed by detecting a signal change in each of the detection
signal lines SDL(1) to SDL(m). In this case, each of the detection
signal lines has one-to-one correspondence with the drive
electrodes, and so it is possible to grasp the touched position by
detecting the signal change in the detection signal lines SDL(1) to
SDL(m).
[0382] FIG. 29 is a circuit diagram illustrating a principle of
touch detection in the case of using the drive electrodes Tx1-1 to
TxN-M arranged in the dot matrix form. Here, the description will
be given by exemplifying the drive electrode TxN-M. In FIG. 29,
numeral OP5 represents an operational amplifier, numeral CP5
represents a capacitive element, and numerals SWD1 to SWD3
represents switches.
[0383] A parasitic capacitance C2 is present between the drive
electrode TxN-M and the ground voltage Vss. First, the switch SWD3
is turned into the on-state, and the switches SWD1 and SWD2 are
turned into the off-state. Accordingly, electric charges stored in
the capacitive element CP5 are discharged via the switch SWD3.
Next, the switch SWD3 is turned into the off-state, and the switch
SWD1 is turned into the on-state. At this time, when the drive
electrode TxN-M is touched by the finger, the electric charges are
also charged by the capacitance with the finger.
[0384] Next, the switch SWD1 is turned into the off-state, and the
switch SWD2 is turned into the on-state. Both inputs of the
operational amplifier OP5 virtually become the same potential (the
ground voltage Vss in FIG. 29) by feedback of the capacitive
element CP5, and so the electric charges stored in the drive
electrode TxN-M are shifted to the capacitive element CP5. Thus, if
the finger touches the drive electrode TxN-M, the electric charges
to be shifted to the capacitive element CP5 increase. As a result,
an absolute value of a voltage outputted from the operational
amplifier OP5 becomes larger. The voltage (signal) outputted from
the operational amplifier OP5 is changed depending on whether the
finger touches the drive electrode TxN-M. The presence or absence
of the touch by the finger is detected by this signal change. That
is, the signal outputted from the operational amplifier OP5 becomes
a sense signal S.
[0385] In this manner, it is possible to detect the touch by the
finger by detecting the signal change in each of the drive
electrodes Tx1-1 to TxN-M. In a detection system illustrated in
FIG. 29, the switch SWD1 is turned into the on-state; the drive
signal is supplied to the drive electrode (for example, TxN-M); and
the signal change in the same drive electrode TxN-M is detected,
thereby detecting the touch by the finger. That is, the touch by
the finger is detected based on the signal change in the drive
electrode to which the drive signal has been supplied. Thus, it is
a so-called capacitive self-detection system.
[0386] The scan lines GL(1) to GL(n) are arranged to be orthogonal
to the detection signal lines SDL(1) to SDL(m) and the signal lines
SL(1) to SL(m) (not illustrated). In the fourth embodiment, the
scan lines GL(1) to GL(n) are used as the signal wiring which
generates the magnetic field at the time of magnetic field touch
detection. That is, the scan lines GL(1) to GL(n) are used as the
drive electrodes TL(0) to TL(p), which have been described in the
first embodiment, in the magnetic field generation period TGT.
Although not particularly limited, a plurality of scan lines are
collectively used as a single drive electrode. In the example
illustrated in FIG. 28, 20 scan lines are provided as a single
bundle. That is, the scan lines GL(1) to GL(20) are provided as a
bundle; the scan lines GL(21) to GL(40) are provided as a bundle;
the scan lines GL(41) to GL(60) are provided as a bundle; the scan
lines GL(61) to GL(80) are provided as a bundle; and the scan lines
GL(n-19) to GL(n) are provided as a bundle.
[0387] The drive signal is supplied to the scan lines used as the
bundle in the magnetic field generation period TGT, similarly to
the first embodiment. For example, the drive signal TSVCOM is
supplied to one end portion of the scan lines GL(1) to GL(20) used
as the bundle from the side 2-L of the display panel 2 side, and
the ground voltage Vss is supplied to the other end portion thereof
from the side 2-R of the display panel 2 side. At this time, for
example, the ground voltage Vss is supplied to one end portion of
the scan lines GL(41) to GL(60) used as the bundle from the side
2-L of the display panel 2 side, and the drive signal TSVCOM is
supplied to the other end portion thereof from the side 2-R of the
display panel 2 side. Accordingly, the magnetic field is generated
around each of the bundle of the scan lines GL(1) to GL(20) and the
bundle of the scan lines GL(41) to GL(60), and the magnetic fields
are superimposed on each other in an area of the scan lines GL(21)
to GL(40).
[0388] In the fourth embodiment, the drive electrodes Tx1-1 to
TxN-M and the detection signal lines SDL(1) to SDL(m) are formed on
the TFT glass substrate TGB, and a magnetic field detection coil is
configured using the detection electrodes RL(0) to RL(p) formed on
the CF glass substrate CGB. The magnetic field detection coil,
which is configured using the detection electrodes RL(0) to RL(p)
formed on the CF glass substrate CGB, has been described already
with reference to FIG. 21, and so the description thereof will be
omitted. In the fourth embodiment, the detection of touch by the
finger is performed by the drive electrodes which are formed on the
TFT glass substrate TGB and arranged in the dot matrix form. Thus,
the detection electrodes RL(0) to RL(p) formed on the CF glass
substrate CGB are not necessarily used for the detection of touch
by the finger, and so the detection electrodes RL(0) to RL(p) can
be fixed in a shape (for example, a coil shape) which is suitable
for detection of the magnetic field.
[0389] In addition, since the plurality of scan lines are handled
as the bundle in the fourth embodiment, it is possible to reduce a
combined resistance of the scan lines in the magnetic field
generation period TGT and to strengthen the generated magnetic
field.
First Modified Example
[0390] In FIG. 28, the description has been given regarding the
case of using the detection electrodes RL(0) to RL(p) formed on the
CF glass substrate CGB for the detection of the magnetic field. In
a first modified example, each of the detection electrodes Tx1-1 to
TxN-M illustrated in FIG. 28 is used for the magnetic field
detection. Accordingly, it is unnecessary to arrange the detection
electrodes RL(0) to RL(p) for the magnetic field detection on the
CF glass substrate CGB, and it is possible to manufacture the
display device 1 with low cost.
Second Modified Example
[0391] FIG. 38 is a plan view illustrating a configuration of the
display device 1 according to a second modified example of the
fourth embodiment. FIG. 38 illustrates the schematic plan view of
the display panel 2. FIG. 38 is similar to FIG. 28, and so a
different point will be described here.
[0392] In the second modified example illustrated in FIG. 38,
detection signal lines SDL(1)P to SDL(m)P, each of which is paired
with the detection signal lines SDL(1) to SDL(m), extend in
parallel to the paired detection signal lines SDL(1) to SDL(m). In
FIG. 28, reference signs SDL(1)P, SDL(2)P and SDL(n)P are attached
only to the detection signal lines, each of which is paired with
the detection signal lines SDL(1), SDL(2) and SDL(n), and reference
signs of the other detection signal lines are not illustrated to
prevent the drawing from being complicated.
[0393] Here, the description will be given by exemplifying one
column (the drive electrodes Tx1-1 to TxN-1) arranged at the
leftmost side in FIG. 38, and the other columns are also configured
in the same manner. The detection signal line SDL(1) and the
detection electrode SDL(1)P extend in parallel to each other and
are connected to the drive electrode Tx1-1, and the detection
signal line SDL(2) and the detection electrode SDL(2)P also extend
in parallel to each other and are connected to the drive electrode
Tx2-1. Hereinafter, the detection signal line SDL(n) and the
detection electrode SDL(n)P extend in parallel to each other and
are connected to the drive electrode TxN-1 in the same manner.
[0394] A magnetic field detection coil is formed using the
detection signal lines extending in parallel as a pair at the time
of magnetic field touch detection. For example, a magnetic field
detection coil is formed using the detection signal lines SDL(1)
and SDL(1)P forming a pair; a magnetic field detection coil is
formed using the detection signal lines SDL(2) and SDL(2)P forming
as a pair; and a magnetic field detection coil is formed using the
detection signal lines SDL(n) and SDL(n)P forming as a pair. In
this case, a signal change of one detection signal lines, for
example, the detection signal lines SDL(1), SDL(2) and SDL(n),
among the detection signal lines each forming a pair is outputted
as the sense signal S. At this time, the ground voltage Vss is
supplied to each of the other detection signal lines SDL(1)P,
SDL(2)P and SDL(n)P among the detection signal lines each forming
the pair.
[0395] Since the magnetic field detection coil is formed using each
of the detection signal lines SDL(1) to SDL(m) and SDL(1)P to
SDL(m)P, it is unnecessary to arrange the detection electrode for
the magnetic field detection on the CF glass substrate CGB, and so
it is possible to manufacture the display device 1 with the low
cost. In addition, the electric field touch detection can be
performed in the same manner as described with reference to FIG.
28.
[0396] In addition, the magnetic field may be detected at the time
of magnetic field touch detection using only a specific pair of
detection signal lines among the plurality of pairs of detection
signal lines arranged on one column (the drive electrodes Tx1-1 to
TxN-1). The detection signal lines SDL(1) and SDL(1)P illustrated
in FIG. 38 correspond to such a specific pair of detection signal
lines. Since the detection signal lines SDL(1) and SDL(1)P are
connected to the drive electrode Tx1-1 arranged on the first row,
the number of scan lines which are orthogonal thereto increases,
and a detectable range at the time of magnetic field touch
detection becomes wide. Accordingly, the detection signal lines
SDL(1) and SDL(1)P are suitably used for the magnetic field touch
detection. A pair of detection signal lines, which is connected to
the drive electrodes Tx1-2 to Tx1-M arranged on the first row among
the plurality of pairs of detection signal lines included in the
respective columns, is used as the magnetic field detection coil at
the time of magnetic field touch detection in the same manner for
other columns of the dot matrix.
Third Modified Example
[0397] FIG. 39 is a plan view illustrating a configuration of the
display device 1 according to a third modified example of the
fourth embodiment. FIG. 39 illustrates the schematic plan view of
the display panel 2. FIG. 39 is similar to FIG. 28, and so a
different point will be described here.
[0398] In FIG. 28, the detection signal line extends to the area
connected to the corresponding drive electrode. In regard to this,
each of the detection signal lines SDL(1) to SDL(m) extends to
cross the display panel 2 in the third modified example. For
example, the detection signal line is arranged to extend from the
side 2-D to the side 2-U of the display panel 2. Here, the
description will be given by exemplifying a first column (the drive
electrodes Tx1-1 to TxN-1) of the dot matrix, and other columns are
also configured in the same manner.
[0399] The detection signal line SDL(1) extends from the side 2-D
to the side 2-U and is connected to the drive electrode Tx1-1 on
the way to the extension, and the detection signal line SDL(2) also
extends from the side 2-D and the side 2-U and is connected to the
drive electrode Tx2-1 on the way to the extension. Next, the
detection signal line SDL(n) also extends from the side 2-D to the
side 2-U and is connected to the drive electrode TxN-1 on the way
to the extension in the same manner.
[0400] On the side 2-U side, the switch SDS is connected between
predetermined detection signal lines. FIG. 39 illustrates only the
switch SDS connected between the detection signal lines SDL(1) and
SDL(2), and the switch SDS connected between the detection signal
lines SDL(3) and SDL(n).
[0401] The switch SDS is turned into the on-state at the time of
magnetic field touch detection, similarly to the eighth switches
k00 to kp illustrated in FIG. 19. Accordingly, a plurality of
detection signal lines are connected to each other. In the example
of FIG. 39, the detection signal lines SDL(1) and SDL(2) are
connected to each other on the side 2-U side. Accordingly, a
magnetic field detection coil is formed using the detection signal
lines SDL(1) and SDL(2) at the time of magnetic field touch
detection. At this time, for example, the ground voltage Vss is
supplied to the detection signal line SDL(2), and a signal change
in the detection signal line SDL(1) is outputted as the sense
signal S.
[0402] Accordingly, since the magnetic field detection coil is
formed using the detection signal lines SDL(1) to SDL(m), it is
unnecessary to arrange the detection electrode for the magnetic
field detection on the CF glass substrate CGB, and so it is
possible to manufacture the display device 1 with the low cost. In
addition, the electric field touch detection can be performed in
the same manner as described with reference to FIG. 28.
[0403] Although the description has been given in FIG. 39 regarding
the example where the magnetic field detection coil is formed using
the adjacent detection signal lines SDL(1) and SDL(2), the
invention is not limited thereto. That is, the detection signal
lines, which are arranged with the detection signal lines
sandwiched therebetween, may be connected using switches to form
magnetic field detection coils that overlap each other. In
addition, a winding with one and half turns or more may be used
instead of the winding with one turn.
Fourth Modified Example
[0404] FIG. 30 is a plan view illustrating a configuration of the
display device 1 according to a fourth modified example of the
fourth embodiment. FIG. 30 is similar to FIG. 28, and so a
different point will be mainly described here. In FIG. 30, numerals
SL(0) to SL(p) represent the signal lines. As described with
reference to FIG. 28, the detection signal lines SDL(1) to SDL(m)
are arranged in parallel to the signal lines SL(0) to SL(p) on the
display panel 2.
[0405] In this modified example, the signal lines SL(0) to SL(p)
are used as a signal wiring to generate a magnetic field. Although
not particularly limited, the plurality of signal lines are
collectively used as a bundle, and the drive signal TSVCOM is
supplied in the magnetic field generation period TGT in this
modified example. When the description is given by exemplifying
FIG. 30, the signal lines SL(0) to SL(19) are collectively used as
a bundle, the signal lines SL(20) to SL(39) are collective used as
a bundle, and the signal lines SL(40) to SL(59) are collectively
used as a bundle in the magnetic field generation period TGT. In
addition, the signal lines SL(k) to SL(k+19) are collectively used
as a bundle, and the signal lines SL(p-19) to SL(p) are
collectively used as a bundle.
[0406] The drive signal is supplied to the bundled signal lines in
the magnetic field generation period TGT. For example, the drive
signal TSVCOM is supplied to one-end portions of the bundled signal
lines SL(0) to SL(19) from the side 2-U of the display panel 2
side, and the ground voltage Vss is supplied to the other-end
portions thereof from the side 2-D of the display panel 2 side. At
this time, for example, the ground voltage Vss is supplied to
one-end portions of the bundled signal lines SL(40) to SL(59) from
the side 2-U of the display panel 2 side, and the drive signal
TSVCOM is supplied to the other-end portions thereof from the side
2-D of the display panel 2 side. Accordingly, a superimposed
magnetic field is formed in an area of the signal lines SL(20) to
SL(39) in the magnetic field generation period TGT.
[0407] In this modified example, a magnetic field detection coil is
configured using the detection electrodes RL(0) to RL(p) formed on
the CF glass substrate CGB, for example. When the magnetic field
detection coil is formed using the detection electrodes RL(0) to
RL(p), each of the detection electrodes RL(0) to RL(p) is formed to
be orthogonal to each of the signal lines SL(0) to SL(p) and to be
parallel to each other, and predetermined detection electrodes are
connected to each other as illustrated in FIG. 21. In addition, the
magnetic field detection coil may be formed using the scan lines
GL(0) to GL(p).
[0408] In addition, the magnetic field may be detected by the
detection electrodes Tx1-1 to TxN-M. If the magnetic field is
detected by the detection electrodes Tx1-1 to TxN-M, for example,
it is unnecessary to arrange the detection electrode for the
magnetic field detection on the CF glass substrate CGB, and it is
possible to manufacture the display device 1 with the low cost.
Fifth Modified Example
[0409] FIG. 40 is a plan view illustrating a configuration of the
display device 1 according to a fifth modified example of the
fourth embodiment. FIG. 40 is similar to FIG. 30, and so a
different point will be mainly described here. In the fifth
modified example, detection signal lines SDL(1)L to SDL(m)L, which
extend in parallel to the respective detection signal lines SDL(1)
to SDL(m), are arranged. In FIG. 40, reference signs SDL(1)L,
SDL(2)L and SDL(n)L are attached only to the detection signal lines
arranged at the drive electrodes Tx1-1 to TxN-1 on the first column
in order to prevent the drawing from being complicated.
[0410] Here, the description will be given by exemplifying the
drive electrodes on the first column, but the other columns are
also configured in the same manner. The detection signal line
SDL(1)L extends in parallel to the detection signal line SDL(1),
and the detection signal line SDL(1) and the detection signal line
SDL(1)L are connected to each other, in an area of the drive
electrode Tx1-1 to which the detection signal line SDL(1) is
connected, so as to form a loop LPP. In addition, the detection
signal line SDL(2)L extends in parallel to the detection signal
line SDL(2), and the detection signal line SDL(2) and the detection
signal line SDL(2)L are connected to each other, in an area of the
drive electrode Tx2-1 to which the detection signal line SDL(2) is
connected, so as to form a loop LPP. In the same manner after this,
the detection signal line SDL(n)L extends in parallel to the
detection signal line SDL(n), and the detection signal line SDL(n)
and the detection signal line SDL(n)L are connected to each other,
in an area of the drive electrode TxN-1 to which the detection
signal line SDL(n) is connected, so as to form a loop LPP.
[0411] Each loop LPP is formed by bending and connecting the
detection signals connected to each other when seen in a plan
view.
[0412] In the fifth modified example, each loop LPP functions as a
magnetic field detection coil. That is, a signal change in one
detection signal line out of the detection signal lines connected
to each other is detected as the sense signal S, and the ground
voltage Vss is supplied to the other detection signal line at the
time of magnetic field touch detection. Accordingly, when the
vicinity of the drive electrode is touched by a pen, a signal
change occurs in the detection signal line forming the loop LPP in
the area of the drive electrode by the magnetic field generated
around the pen, and the touch by the pen and a coordinate thereof
can be obtained.
[0413] For example, when each of the detection signal lines
SDL(1)L, SDL(2)L to SDL(n)L is set as the other detection signal
line between the detection signal lines forming each loop, the
ground voltage Vss is supplied to each of the detection signal
lines SDL(1)L, SDL(2)L to SDL(n)L. At this time, the signal change
in each of the detection signal lines SDL(1) and SDL(2) to SDL(n),
which serves as one detection signal line between the detection
signal lines forming each loop, is detected as the sense signal S.
Accordingly, it is possible to make the detection about which part
of the first column the pen is touched at, and simultaneously to
make the detection about which row (which area out of the drive
electrodes Tx1-1 to TxN-1) of the first column the touch is
performed at (in).
[0414] Since the detection signal line is also used as the magnetic
field detection coil in the fifth modified example, it is possible
to manufacture the display device 1 with the low cost. In addition,
the electric field touch detection can be performed in the same
manner as the fourth modified example. Further, the detection
signal line can be shared between the magnetic field detection and
the electric field detection, and so it is possible to suppress the
increase of price of the display device which is capable of the
magnetic field touch detection and the electric field touch
detection.
Fifth Embodiment
[0415] In the first to fourth embodiments, the description has been
given mainly regarding the example where the magnetic field is
generated in the magnetic field generation period TGT using the
signal wiring orthogonal to the signal lines SL(0) to SL(p) in the
display panel 2. In a fifth embodiment, the description will be
given regarding an example where a magnetic field is generated in
the magnetic field generation period TGT using a signal wiring
arranged in parallel to the signal lines SL(0) to SL(p) in the
display panel 2. Here, the description will be given regarding a
case where drive electrodes are used as the signal wiring arranged
in parallel to the signal lines SL(0) to SL(p).
[0416] FIG. 31 is a plan view schematically illustrating a
configuration of the display device 1 according to the fifth
embodiment. FIG. 31 illustrates a part relating to the display
panel 2. Although the plurality of signal lines SL(0) to SL(p), the
plurality of scan lines GL(0) to GL(p), the plurality of drive
electrodes TL(0) to TL(p) and the like are arranged in the display
panel 2. However, FIG. 31 illustrates the display panel 2 in which
the signal lines SL(0) to SL(7), the scan lines GL(0) to GL(3), and
the drive electrodes TL(0) to TL(7) are arranged to make the
description easy. The signal lines SL(0) to SL(7) extend in the
column direction and are arranged in parallel in the row direction
in the display panel 2. In the fifth embodiment, the drive
electrodes TL(0) to TL(7) to which the drive signal is supplied in
the magnetic field generation period TGT are arranged in parallel
to the signal lines SL(0) to SL(7). That is, the drive electrodes
TL(0) to TL(7) also extend in the column direction and are arranged
in parallel in the row direction in the display panel 2.
[0417] The scan lines GL(0) to GL(3) extend in the row direction
and are arranged in parallel in the column direction in the display
panel 2. In the fifth embodiment, gate drivers 5-1 and 5-2 are
arranged along the side 2-L and the side 2-R of the display panel
2, respectively, although not particularly limited thereto. The
scan lines GL(0) to GL(3) are connected to the gate driver 5-1 on
the side 2-L side and are connected to the gate driver 5-2 on the
side 2-R side. When display is performed in the display panel 2,
for example, the gate driver 5-1 supplies a scan line signal with a
high level to the scan line GL(0), and the gate driver 5-2 supplies
the scan line signal with the high level to the next scan line
GL(1) at the next timing. That is, the scan line signal with the
high level is supplied to the scan lines GL(0) to GL(3) alternately
from the gate drivers 5-1 and 5-2. Accordingly, it is possible to
prevent the increase of the frame.
[0418] In FIG. 31, numeral 3 represents a signal line selector. The
signal line selector 3 has been described with reference to FIG. 8
and the like, and so the description thereof will be omitted. In
FIG. 31, numerals SCW-D and SCW-U represent connection circuits
which electrically connect the signal lines SL(0) to SL(7) and the
common electrodes TL(0) to TL(7), which overlap each other when
seen in a plan view, during the touch detection. That is, the
connection circuit SCW-D connects the drive electrode TL(0) and the
signal line SL(0) on the side 2-D side, and the connection circuit
SCW-U connects the drive electrode TL(0) and the signal line SL(0)
on the side 2-U side during the touch detection. Similarly, the
drive electrode TL(1) and the signal line SL(1) are connected by
the connection circuits SCW-D and SCW-U during the touch detection.
Similarly, the remaining drive electrodes and signal lines are also
electrically connected during the touch detection. Accordingly, the
drive electrodes and the signal lines, which overlap each other
when seen in a plan view, are connected in parallel during the
touch detection, and it is possible to achieve the reduction of the
combined resistance.
[0419] In FIG. 31, numerals SU-R and SD-R represent drive circuits,
and numerals SU-C and SD-C represent selection circuits. Similarly
to the first embodiment, a selection drive circuit (a first drive
circuit or a second drive circuit) SSU is configured using the
drive circuit SU-R and the selection circuit SU-C, and a selection
drive circuit (a second drive circuit or a first drive circuit) SSD
is configured using the drive circuit SD-R and the selection
circuit SD-C. The selection drive circuit SSU is arranged along the
side 2-U of the display panel 2, and the selection drive circuit
SSD is arranged along the side 2-D of the display panel 2.
[0420] The selection drive circuit SSU supplies a drive signal from
the side 2-U side to one drive electrode out of the selected pair
of drive electrodes and supplies the ground voltage Vss to the
other drive electrode in the magnetic field generation period TGT
for the magnetic field touch detection. In addition, the selection
drive circuit SSD supplies the ground voltage Vss from the side 2-D
side to the other drive electrode out of the above-described pair
of drive electrodes and supplies the drive signal to the one drive
electrode. Accordingly, a strong superimposed magnetic field is
generated between the selected pair of drive electrodes in the
magnetic field generation period TGT.
[0421] In FIG. 31, numeral VCOM represents a voltage wiring to
which a predetermined voltage VCOMDC is supplied. In addition,
numeral TPL represents a voltage wiring to which the ground voltage
Vss is supplied, and numeral TPH represents a voltage wiring to
which a predetermined voltage (for example, the voltage Vp
illustrated in FIGS. 15A to 15C) is supplied. The selection drive
circuits SSU and SSD connect the voltage wiring TPL to the selected
drive electrode in order to supply the ground voltage Vss to the
selected drive electrode. In addition, the selection drive circuits
SSU and SSD connect the voltage wiring TPH to the selected drive
electrode in order to supply the drive signal to the selected drive
electrode.
[0422] A magnetic field detection coil is configured using the
detection electrodes RL(0) to RL(p) formed on the CF glass
substrate CGB, for example. In the fifth embodiment, the detection
electrodes RL(0) to RL(p) extend in the row direction and are
arranged in parallel in the column direction in the display panel
2, similarly to the scan line. In addition, the predetermined
detection electrodes are connected to form the magnetic field
detection coil in the magnetic field detection period TDT. In
addition, the magnetic field detection coil may be formed using the
scan lines GL(0) to GL(3).
[0423] In the fifth embodiment, the selection drive circuit SSD
supplies the drive signal to the selected drive electrode at the
time of electric field touch detection. Accordingly, an electric
field is generated around the selected drive electrode. In this
case, a change in the electric field is detected by the detection
electrodes RL(0) to RL(p) or the scan lines GL(0) to GL(3) formed
on the CF glass substrate CGB, for example.
[0424] Incidentally, each of the gate drivers 5-1 and 5-2 has a
function of turning the scan lines GL(0) to GL(3) into the floating
state, and turns the scan lines GL(0) to GL(3) into the floating
state, for example, in the magnetic field generation period TGT
although not particularly limited.
<Configuration of Selection Drive Circuit>
[0425] FIG. 32 is a circuit diagram illustrating each configuration
of the selection drive circuits SSU and SSD according to the fifth
embodiment. FIG. 32 is drawn in accordance with actual arrangement
although being schematic. FIG. 32 illustrates the drive electrodes
TL(0) to TL(6) among the drive electrodes TL(0) to TL(7)
illustrated in FIG. 31, and each part of the selection drive
circuits SSU and SSD corresponding to these drive electrodes TL(0)
to TL(6).
[0426] As illustrated in FIG. 31, the selection drive circuit SSU
is arranged along the side 2-U of the display panel 2, and the
selection drive circuit SSD is arranged along the side 2-D of the
display panel 2. The drive circuit SU-R inside the selection drive
circuit SSU is provided with unit drive circuits USU(0) to USU(6)
which correspond to the respective drive electrodes TL(0) to TL(6)
and which are arranged along the side 2-U. Similarly, the drive
circuit SD-R inside the selection drive circuit SSD is provided
with unit drive circuits USD(0) to USD(6) which correspond to the
respective drive electrodes TL(0) to TL(6) and which are arranged
along the side 2-D.
[0427] In the fifth embodiment, the voltage wirings TPL and TPH are
arranged to surround the display panel 2. When the description is
given by exemplifying the module illustrated in FIG. 9, the voltage
wirings TPL and TPH are arranged to pass through an area between
the side 2-L of the display panel 2 and the side 900-L of the
module 900, an area between the side 2-U of the display panel 2 and
the side 900-U of the module 900, an area between the side 2-R of
the display panel 2 and the side 900-R of the module 900, and an
area between the side 2-D of the display panel 2 and the side 900-D
of the module 900. That is, the voltage wirings TPL and TPH are
arranged in upper, lower, right and left frames of the module 900.
Meanwhile, the voltage wiring VCOM is arranged in the area between
the side 2-D of the display panel 2 and the side 900-D of the
module 900.
[0428] The selection circuit SU-C inside the selection drive
circuit SSU is provided with unit selection circuits UUC(0) to
UUC(6) which correspond to the respective unit drive circuits
USU(0) to USU(6) in the fifth embodiment. Each of the unit
selection circuits UUC(0) to UUC(6) is provided with a tenth switch
USW1 and an eleventh switch USW2. In each of the unit selection
circuits UUC(0) to UUC(6), the tenth switch USW1 is connected
between the voltage wiring TPH and one end portion of the
corresponding drive electrode and is subjected to switch control by
a selection signal sent from the corresponding unit drive circuit;
and the eleventh switch USW2 is connected between the voltage
wiring TPL and one end portion of the corresponding drive electrode
and is subjected to switch control by a selection signal sent from
the corresponding unit drive circuit.
[0429] That is, the tenth switch USW1 is connected between the
voltage wiring TPH and one end portion of the drive electrode TL(0)
and is subjected to switch control by a selection signal C10 sent
from the unit selection circuit USU(0) in the unit selection
circuit UUC(0). In addition, the eleventh switch USW2 is connected
between the voltage wiring TPL and the one end portion of the drive
electrode TL(0) and is subjected to switch control by a selection
signal C20 sent from the unit selection circuit USU(0) in the unit
selection circuit UUC(0). In the unit selection circuit UUC(1),
each of the tenth switch USW1 and the eleventh switch USW2 is
connected between each of the voltage wirings TPH and TPL and one
end portion of the drive electrode TL(1) and is subjected to switch
control by each of selection signals C11 and C21 sent from the unit
selection circuit USU(1). In the unit selection circuit UUC(2),
each of the tenth switch USW1 and the eleventh switch USW2 is
connected between each of the voltage wirings TPH and TPL and one
end portion of the drive electrode TL(2) and is subjected to switch
control by each of selection signals C12 and C22 sent from the unit
selection circuit USU(2).
[0430] Similarly, each of the tenth switch USW1 and the eleventh
switch USW2 is connected between each of the voltage wirings TPH
and TPL and one end of the drive electrode TL(3) and is subjected
to switch control by each of selection signals C13 and C23 sent
from the unit selection circuit USU(3) in the unit selection
circuit UUC(3). Each of the tenth switch USW1 and the eleventh
switch USW2 is connected between each of the voltage wirings TPH
and TPL and one end portion of the drive electrode TL(4) and is
subjected to switch control by each of selection signals C14 and
C24 sent from the unit selection circuit USU(4) in the unit
selection circuit UUC(4). Each of the tenth switch USW1 and the
eleventh switch USW2 is connected between each of the voltage
wirings TPH and TPL and one end portion of the drive electrode
TL(5) and is subjected to switch control by each of selection
signals C15 and C25 sent from the unit selection circuit USU(5) in
the unit selection circuit UUC(5). Each of the tenth switch USW1
and the eleventh switch USW2 is connected between each of the
voltage wirings TPH and TPL and one end portion of the drive
electrode TL(6) and is subjected to switch control by each of
selection signals C16 and C26 sent from the unit selection circuit
USU(6) in the unit selection circuit UUC(6).
[0431] The drive circuit SD-R inside the selection drive circuit
SSD is also provided with the unit drive circuits USD(0) to USD(6)
which correspond to the respective drive electrodes TL(0) to TL(6).
In addition, the selection circuit SD-L is provided with unit
selection circuits UDC(0) to UDC(6) which correspond to the
respective drive electrodes and unit drive circuits. Each of the
unit selection circuits UDC(0) to UDC(6) is provided with a twelfth
switch USW3, a thirteenth switch USW4, and a fourteenth switch USW5
which are subjected to switch control by control signals sent from
the corresponding unit selection circuits. Here, the twelfth switch
USW3 is connected between the other end portion of the
corresponding drive electrode and the voltage wiring VCOM; the
thirteenth switch USW4 is connected between the other end portion
of the corresponding drive electrode and the voltage wiring TPL;
and the fourteenth switch USW5 is connected between the other end
portion of the corresponding drive electrode and the voltage wiring
TPH.
[0432] That is, the twelfth switch USW3 is connected between the
other end portion of the drive electrode TL(0) and the voltage
wiring VCOM; the thirteenth switch USW4 is connected between the
other end portion of the drive electrode TL(0) and the voltage
wiring TPL; and the fourteenth switch USW5 is connected between the
other end portion of the drive electrode TL(0) and the voltage
wiring TPH in the unit selection circuit UDC(0). In addition, the
twelfth switch USW3 in the unit selection circuit UDC(0) is
subjected to switch control by a selection signal S30 sent from the
unit drive circuit USD(0); the thirteenth switch USW4 is subjected
to switch control by a selection signal S40 sent from the unit
drive circuit USD(0); and the fourteenth switch USW5 is subjected
to switch control by the selection signal S40 sent from the unit
drive circuit USD(0).
[0433] In addition, each of the twelfth switch USW3, the thirteenth
switch USW4, and the fourteenth switch USW5 is connected between
the other end portion of the drive electrode TL(1) and each of the
voltage wirings VCOM, TPL and TPH and is subjected to switch
control by selection signals S31 and S41 sent from the unit drive
circuit USD(1) in the unit selection circuit UDC(1). Each of the
twelfth switch USW3, the thirteenth switch USW4, and the fourteenth
switch USW5 is connected between the other end portion of the drive
electrode TL(2) and each of the voltage wirings VCOM, TPL and TPH
and is subjected to switch control by selection signals S32 and S42
sent from the unit drive circuit USD(2) in the unit selection
circuit UDC(2). In the unit selection circuit UDC(3), each of the
twelfth switch USW3, the thirteenth switch USW4, and the fourteenth
switch USW5 is connected between the other end portion of the drive
electrode TL(3) and each of the voltage wirings VCOM, TPL and TPH
and is subjected to switch control by selection signals S33 and S43
sent from the unit drive circuit USD(3).
[0434] Similarly, each of the twelfth switch USW3, the thirteenth
switch USW4, and the fourteenth switch USW5 is connected between
the other end portion of the drive electrode TL(4) and each of the
voltage wirings VCOM, TPL and TPH and is subjected to switch
control by selection signals S34 and S44 sent from the unit drive
circuit USD(4) in the unit selection circuit UDC(4). Each of the
twelfth switch USW3, the thirteenth switch USW4, and the fourteenth
switch USW5 is connected between the other end portion of the drive
electrode TL(5) and each of the voltage wirings VCOM, TPL and TPH
and is subjected to switch control by selection signals S35 and S45
sent from the unit drive circuit USD(5) in the unit selection
circuit UDC(5). In addition, each of the twelfth switch USW3, the
thirteenth switch USW4, and the fourteenth switch USW5 is connected
between the other end portion of the drive electrode TL(6) and each
of the voltage wirings VCOM, TPL and TPH and is subjected to switch
control by selection signals S36 and S46 sent from the unit drive
circuit USD(6) in the unit selection circuit UDC(6).
[0435] Figure is illustrated so that the thirteenth switch USW4 and
the fourteenth switch USW5 are subjected to the switch control by
the single selection signal (for example, the selection signal S40)
in each of the unit selection circuits UDC(0) to UDC(6) in order to
prevent the drawing from being complicated, but the thirteenth
switch USW4 and the fourteenth switch USW5 are separately
switch-controlled by the corresponding unit drive circuit.
[0436] In the fifth embodiment, the drive signal or the ground
voltage Vss is supplied to the drive electrode corresponding to the
unit drive circuit which indicates selection in the magnetic field
generation period TGT, similarly to the description in FIG. 22. In
this case, the drive signal corresponds to the predetermined
voltage in the voltage wiring TPH, and the supply of the
predetermined voltage of the voltage wiring TPH to the drive
electrode corresponds to the supply of the drive signal.
[0437] Each of the unit drive circuits USU(0) to USU(6) has a shift
stage, and the respective shift stages are connected in series in
this order. Similarly, each of the unit drive circuits USD(0) to
USD(6) also has a shift stage, and the respective shift stages are
connected in series in this order. For example, the selection
information SEI indicating the selection is set to the unit drive
circuits USU(0), USU(1), USD(0) and USD(1), and the selection
information SEI is sequentially shifted to the unit drive circuit
USU(6) and USD(6) in synchronization with a clock signal (not
illustrated).
[0438] For example, when the selection information SEI indicating
the selection is set to the unit drive circuits USU(0), USU(1),
USD(0) and USD(1), the unit drive circuit USU(0) turns the eleventh
switch USW2 inside the unit selection circuit UUC(0) into the
on-state using the selection signal S20, and turns the tenth switch
USW1 into the off-state using the selection signal S10 in the
magnetic field generation period TGT. At this time, the unit drive
circuit USU(1) turns the tenth switch USW1 inside the unit
selection circuit UUC(1) into the on-state using the selection
signal S11, and turns the eleventh switch USW2 into the off-state
using the selection signal S21.
[0439] In addition, at this time, the unit drive circuit USD(0)
turns the fourteenth switch USW5 into the on-state using the
selection signal S40, and turns the thirteenth switch USW4 into the
off-state. In addition, the unit drive circuit USD(0) turns the
twelfth switch USW3 into the off-state using the selection signal
S30. Further, at this time, the unit drive circuit USD(1) turns the
thirteenth switch USW4 into the on-state using the selection signal
S41, and turns the fourteenth switch USW5 into the off-state. In
addition, the unit drive circuit USD(1) turns the twelfth switch
USW3 into the off-state using the selection signal S30.
[0440] Accordingly, the one end portion of the drive electrode
TL(0) is connected to the voltage wiring TPL via the eleventh
switch USW2 inside the unit selection circuit UUC(0), and the other
end portion of the drive electrode TL(1) is connected to the
voltage wiring TPL via the thirteenth switch USW4 inside the unit
selection circuit UDC(1). At this time, the other end portion of
the drive electrode TL(0) is connected to the voltage wiring TPH
via the fourteenth switch USW5 inside the unit selection circuit
UDC(0); and the one end portion of the drive electrode TL(1) is
connected to the voltage wiring TPH via the tenth switch USW1
inside the unit selection circuit UUC(1). As a result, the ground
voltage Vss is supplied to the one end portion of the drive
electrode TL(0) and the other end portion of the drive electrode
TL(1); and the predetermined voltage is supplied to the other end
portion of the drive electrode TL(0) and the one end portion of the
drive electrode TL(1) as the drive signal.
[0441] A current flows in the drive electrode TL(0) in a direction
from the other end portion toward the one end portion thereof
(upward direction in the drawing) by the predetermined voltage; a
current flows in the drive electrode TL(1) in a direction from the
one end portion toward the other end portion (downward direction in
the drawing); a magnetic field is generated around each of the
drive electrodes TL(0) and TL(1); and the magnetic fields are
superimposed on each other in an area sandwiched between the drive
electrodes TL(0) and TL(1).
[0442] Incidentally, each of the unit drive circuits USU(2) to
USU(6) turns the tenth switch USW1 and the eleventh switch USW2 in
each of the corresponding unit selection circuits UUC(2) to UUC(6)
into the off-state using the selection signals S12 to S16 and S22
to S26 at this time. In addition, each of the unit drive circuits
USD(2) to USD(6) turns the twelfth switch USW3, the thirteenth
switch USW4, and the fourteenth switch USW5 in each of the
corresponding unit selection circuits UDC(2) to UDC(6) into the
off-state using the selection signals S32 to S36 and S42 to S46 at
this time. As a result, each of the drive electrodes TL(2) to TL(6)
is turned into a high impedance state.
[0443] When the selection information SEI is shifted to the unit
drive circuits USU(1), USU(2), UDC(1) and UDC(2) as the clock
signal changes, the unit drive circuit USU(1) turns the tenth
switch USW1 inside the unit selection circuit UUC(1) into the
off-state, and turns the eleventh switch USW2 into the on-state
using the selection signals S11 and S21. At this time, the unit
drive circuit USU(2) turns the tenth switch USW1 inside the unit
selection circuit UUC(2) into the on-state and turns the eleventh
switch USW2 into the off-state using the selection signals S11 and
S21. In addition, the unit selection circuit USD(1) turns the
fourteenth switch USW5 inside the unit selection circuit UDC(1)
into the on-state, and turns the twelfth switch USW3 and the
thirteenth switch USW4 into the off-state using the selection
signals S31 and S41. In addition, the unit selection circuit USD(2)
turns the thirteenth switch USW4 inside the unit selection circuit
UDC(2) into the on-state, and turns the twelfth switch USW3 and the
fourteenth switch USW5 into the off-state using the selection
signals S32 and S42.
[0444] As a result, a current flows in the drive electrode TL(1)
from the other end portion toward the one end portion thereof and a
current flows in the drive electrode TL(2) from the one end portion
toward the other end portion thereof. The magnetic fields are
generated around the drive electrodes TL(1) and TL(2) due to these
currents, thereby generating the superimposed magnetic field. At
this time, the tenth switch to the fourteenth switch in each of the
unit selection circuits UUC(0), UUC(3) to UUC(6), UDC(0) and UDC(3)
to UDC(6) are turned into the off-state, and the drive electrodes
TL(0) and TL(3) to TL(6) are turned into the high impedance
state.
[0445] After this, the magnetic field is sequentially generated
according to the shift of the selection information SEI toward the
unit drive circuits USU(6) and USD(6) in synchronization with the
clock signal. That is, the magnetic fields are generated around the
drive electrodes TL(2) and TL(3); the magnetic fields are generated
around the drive electrodes TL(3) and TL(4) at the subsequent
timing; the magnetic fields are generated around the drive
electrodes TL(4) and TL(5) at the further subsequent timing; and
then the magnetic fields are generated around the drive electrodes
TL(5) and TL(6).
[0446] The direction of the current flowing in the drive electrode
is not limited to the above-described direction. For example, when
the drive electrodes TL(0) and TL(1) are caused to generate the
magnetic fields, the current may flow in the drive electrode TL(0)
in a direction from the one end portion toward the other end
portion thereof, and flow in the drive electrode TL(1) from the
other end portion toward the one end portion thereof. That is, the
respective directions of the currents may be opposite to each other
between the pair of drive electrodes adjacently arranged.
[0447] Although the description has been given regarding the
example of using the drive electrodes arranged to be adjacent to
each other, the invention is not limited thereto. For example, the
magnetic field may be generated by the drive electrodes which are
arranged to sandwich one or a plurality of drive electrodes. For
example, the selection information SEI indicating selection may be
set to the unit drive circuits USU(0), USC(2), USD(0) and USD(2).
In this manner, the magnetic field is generated around the pair of
drive electrodes TL(0) and TL(2) arranged to sandwich the drive
electrode TL(1). Subsequently, the magnetic fields are sequentially
generated around the drive electrodes arranged to sandwich one
drive electrode as the selection information SEI is shifted in
synchronization with the change of the clock signal.
[0448] At the time of electric field touch detection, each of the
unit drive circuits USU(0) to USU(6) turns the tenth switch USW1
and the eleventh switch USW2 inside the corresponding unit
selection circuits UUC(0) to UUC(6) into the off-state using the
selection signals S10 to S16 and S20 to S26. Meanwhile, the
selection information SEI is sequentially shifted in the unit drive
circuits USD(0) to USD(6). For example, when the selection
information SEI is set to the unit drive circuit USD(0), the unit
drive circuit USD(0) turns the twelfth switch USW3 into the
on-state using the selection signal S30. Accordingly, the drive
electrode TL(0) is connected to the voltage wiring VCOM via the
twelfth switch USW3. In the fifth embodiment, the control circuit
D-CNT (FIG. 8) supplies an electric field drive signal with
periodically changing voltage to the voltage wiring VCOM in the
case of electric field touch detection. Accordingly, the drive
electrode TL(0) generates an electric field according to the
electric field drive signal at the time of electric field touch
detection.
[0449] Incidentally, the thirteenth switch USW4 and the fourteenth
switch USW5 in the unit selection circuit UDC(0) are turned into
the off-state at this time. In addition, the twelfth switch USW3,
the thirteenth switch USW4, and the fourteenth switch USW5 in each
of the remaining unit selection circuits USD(1) to USD(6) are also
turned into the off-state.
[0450] As the selection information SEI is shifted from the unit
drive circuit USD(0) toward USD(6), the electric fields are
sequentially generated from the drive electrode TL(2) toward
TL(6).
[0451] Although the description has been given regarding the
example where the electric field drive signal with the periodically
changing voltage is supplied to the voltage wiring VCOM at the time
of electric field touch detection, the invention is not limited
thereto. For example, the thirteenth switch USW4 and the fourteenth
switch USW5 may be complementarily turned into the on/off state
using the selection signal S40 instead of turning the twelfth
switch USW3 into the on-state using the selection signal S30. As
the thirteenth switch USW4 and the fourteenth switch USW5 are
complementarily turned into the on/off state, the drive electrode
TL(0) is alternately connected to the voltage wirings TPH and TPL.
As a result, the voltage that changes with time is supplied to the
drive electrode TL(0), and it is possible to generate the electric
field that changes with time.
[0452] The magnetic field detection coil can be formed using the
detection electrodes RL(0) to RL(p) or the scan lines GL(0) to
GL(p) at the time of magnetic field touch detection, similarly to
the description in the fourth embodiment. In addition, for example,
the scan line can be used as the detection electrode to detect the
change of the electric charge amount at the time of electric field
touch detection.
Modified Example
[0453] FIG. 33 is a circuit diagram illustrating configurations of
selection drive circuits SSU and SSD according to a modified
example of the fifth embodiment. FIG. 33 is drawn in accordance
with actual arrangement although being schematic. FIG. 33 is
similar to FIG. 32, and so a different point will be mainly
described here.
[0454] In the configuration illustrated in FIG. 32, each of the
voltage wirings TPL and TPH is arranged to surround the display
panel 2. In regard to this, the voltage wiring TPL is arranged in
an area between the side 2-L of the display panel 2 and the side
900-L of the module 900 (FIG. 9), and the voltage wiring TPH is
arranged in an area between the side 2-R of the display panel 2 and
the side 900-R of the module 900 in the modified example
illustrated in FIG. 33. In other words, the voltage wiring TPH is
not arranged in the area between the side 2-L of the display panel
2 and the side 900-L of the module 900 (FIG. 9), and the voltage
wiring TPL is not arranged in the area between the side 2-R of the
display panel 2 and the side 900-R of the module 900 (FIG. 9). That
is, only one of the voltage wirings TPH and TPL is arranged in the
right and left frames.
[0455] In the modified example, the voltage wirings TPL and TPH are
arranged in an area between the side 2-U of the display panel 2 and
the side 900-U of the module 900, and the voltage wirings TPL and
TPH are also arranged in an area between the side 2-D of the
display panel 2 and the side 900-D of the module 900. In addition,
the voltage wiring TPL arranged in the area between the side 2-U
and the side 900-U is connected to the voltage wiring TPL arranged
in the area between the side 2-D and the side 900-D via the voltage
wiring TPL arranged in the area between the side 2-L and the side
900-L. Further, the voltage wiring TPH arranged in the area between
the side 2-U and the side 900-U is connected to the voltage wiring
TPR arranged in the area between the side 2-D and the side 900-D
via the voltage wiring TPR arranged in the area between the side
2-R and the side 900-R.
[0456] Accordingly, it is possible to supply the ground voltage Vss
and the predetermined voltage to the selection drive circuit SSU
arranged along the side 2-U of the display panel 2 and the
selection drive circuit SSD arranged along the side 2-D of the
display panel 2 while suppressing the increase of the frame.
Sixth Embodiment
[0457] FIG. 34 is a schematic plan view illustrating a
configuration of the display device 1 according to a sixth
embodiment. FIG. 34 is also drawn in accordance with actual
arrangement although being schematic. In the display device 1
according to the sixth embodiment, the description will be given
also regarding an example where a magnetic field is generated in
the magnetic field generation period TGT using a drive electrode
arranged in parallel to the signal lines SL(0) to SL(p) similarly
to the fifth embodiment.
[0458] FIG. 34 illustrates a part relating to the display panel 2
similarly to FIG. 31. FIG. 34 is similar to FIG. 31, and so a
different point will be mainly described here. In FIG. 31, the
predetermined voltage serving as the drive signal and the ground
voltage Vss are supplied to the pair of drive electrodes by the
selection drive circuit SSU including the drive circuit SU-R and
the selection circuit SU-C in the magnetic field generation period
TGT to generate the magnetic field. Thus, the voltage wirings TPL
and TPH are arranged along the side 2-U of the display panel 2, and
the ground voltage Vss and the predetermined voltage are supplied
to the selection circuit SU-C.
[0459] In the sixth embodiment, the selection drive circuit SSU-S
is also arranged along the side 2-U of the display panel 2. The
selection drive circuit SSU-S according to the sixth embodiment is
provided with the drive circuit SU-R and a selective connection
circuit SU-S. The selective connection circuit SU-S is different
from the selection circuit SU-C that has been described in the
fifth embodiment, and forms a magnetic field generation coil by
connecting signal wirings arranged to be parallel to the signal
lines SL(0) to SL(p) to each other in the magnetic field generation
period TGT. Here, drive electrodes and voltage wirings arranged
along the sides 2-L and 2-R of the display panel 2 correspond to
the signal wirings arranged to be parallel to the signal lines
SL(0) to SL(p).
[0460] In the case of focusing on the voltage wiring TPH arranged
in the area between the side 2-L of the display panel 2 and the
side 900-L of the module 900 and the voltage wiring TPL arranged in
the area between the side 2-R of the display panel 2 and the side
900-R of the module 900, both voltage wirings are used to supply
the predetermined voltage and the ground voltage Vss to the
selection circuit SU-C in the fifth embodiment. In regard to this,
the voltage wirings TPL and TPH, which are arranged along the side
2-L and the side 2-R of the display panel 2, are also used as
windings of a magnetic field generation coil in the sixth
embodiment although not particularly limited thereto.
<Configuration of Selective Connection Circuit>
[0461] FIG. 35 is a circuit diagram illustrating a configuration of
the selection drive circuit SSU-S according to the sixth
embodiment. FIG. 35 is drawn in accordance with actual arrangement
although being schematic. In FIG. 35, the selection drive circuit
SSD and the drive electrodes TL(0) to TL(6) are the same as those
in FIG. 32, and so the description thereof will be omitted.
[0462] Similarly to FIG. 32, the drive circuit SU-R includes the
plurality of unit drive circuits USU(0) to USU(6). Each of the unit
drive circuits USU(0) to USU(6) has the shift stage. The respective
shift stages of the unit drive circuits USU(0) to USU(6) are
connected in series, and the selection information SEI set to the
unit drive circuit USU(0) is shifted toward the unit drive circuit
USU(6) in synchronization with a clock signal (not illustrated).
Each of the unit drive circuits USU(0) to USU(6) outputs selection
signals S50 to S56 indicating selection as the selection
information SEI indicating selection is set thereto. For example,
the unit drive circuit USU(3) outputs the selection signal S53
indicating the selection when the selection information SEI
indicating the selection is shifted from the unit drive circuit
USU(2) at the previous stage and is supplied thereto.
[0463] The selective connection circuit SU-S includes fifteenth
switches USW6(0) to USW6(6) which correspond to the unit drive
circuits USU(0) to USU(6), respectively. Each of the fifteenth
switches USW6(0) to USW(6) is connected among each of the drive
electrodes TL(0) to TL(6), a voltage wiring TL(TPH) arranged along
the side 2-L of the display panel 2, and a voltage wiring TL(TPL)
arranged along the side 2-R of the display panel 2 so that one
drive electrode is sandwiched therebetween. In FIG. 35, the voltage
wiring TL(TPH) represents an area arranged along the side 2-L of
the display panel 2 in the voltage wiring TPH, and the voltage
wiring TL(TPL) represents an area arranged along the side 2-R of
the display panel 2 in the voltage wiring TPL. The voltage wirings
TL(TPH) and TL(TPL) are arranged along the side 2-L and the side
2-R of the display panel 2, and thus are parallel to the drive
electrodes TL(0) to TL(6).
[0464] The fifteenth switch USW6(0) is connected between the
voltage wiring TL(TPH) and one end portion of the drive electrode
TL(1) and is subjected to switch control by the selection signal
S50 sent from the unit drive circuit USU(0); the fifteenth switch
USW6(1) is connected between the one end portions of the respective
drive electrode TL(0) and drive electrode TL(2), and is subjected
to switch control by the selection signal S51 sent from the unit
drive circuit USU(1); and the fifteenth switch USW6(2) is connected
between one end portions of the respective drive electrode TL(1)
and drive electrode TL(3), and is subjected to switch control by
the selection signal S52 sent from the unit drive circuit USU(2).
In addition, the fifteenth switch USW6(3) is connected between one
end portions of the respective drive electrode TL(2) and drive
electrode TL(4), and is subjected to switch control by the
selection signal S53 sent from the unit drive circuit USU(3); and
the fifteenth switch USW6(4) is connected between one end portions
of the respective drive electrode TL(3) and drive electrode TL(5),
and is subjected to switch control by the selection signal S54 sent
from the unit drive circuit USU(4).
[0465] Similarly, the fifteenth switch USW6(5) is connected between
one end portions of the respective drive electrode TL(4) and drive
electrode TL(6), and is subjected to switch control by the
selection signal S55 sent from the unit drive circuit USU(5); and
the fifteenth switch USW6(6) is connected between one end portion
of the drive electrode TL(5) and the voltage wiring TL(TPL), and is
subjected to switch control by the selection signal S56 sent from
the unit drive circuit USU(6).
[0466] In the sixth embodiment, when the unit drive circuit USU(0)
outputs the selection signal S50 indicating the selection in the
magnetic field generation period TGT, the unit drive circuit USD(1)
outputs the selection signal S41 so that the thirteenth switch USW4
inside the unit selection circuit UDC(1) is turned into the
on-state, and that the fourteenth switch USW5 is turned into the
off-state. Since the fifteenth switch USW6(0) is turned into the
on-state by the selection signal S50, the voltage wiring TL(TPH)
and the drive electrode TL(1), which are arranged in parallel to
each other, are connected in series. As a result, a magnetic field
generation coil using the voltage wiring TL(TPH) and the drive
electrode TL(1) as a winding is formed. When a current flows in the
voltage wiring TL(TPH) and the drive electrode TL(1) connected in
series, a magnetic field is generated around each of the voltage
wiring TL(TPH) and the drive electrode TL(1). The generated
magnetic fields are superimposed on each other in an area of the
drive electrode TL(0) sandwiched between the voltage wiring TL(TPH)
and the drive electrode TL(1), thereby generating a strong magnetic
field.
[0467] Next, when the selection information SEI indicating the
selection is shifted to the unit drive circuit USU(1), the
fifteenth switch USW6(1) is turned into the on-state by the
selection signal S51. At this time, the unit drive circuit USD(0)
outputs the selection signal S40 so that the fourteenth switch USW5
inside the unit selection circuit UDC(0) is turned into the
on-state and the thirteenth switch USW4 is turned into the
off-state. In addition, the unit selection circuit UDC(2) outputs
the selection signal S42 so that the thirteenth switch USW4 inside
the unit selection circuit UDC(2) is turned into the on-state and
the fourteenth switch USW5 is turned into the off-state. Since the
fifteenth switch USW6(1) is turned into the on-state, the drive
electrodes TL(0) and TL(2), which are arranged in parallel to each
other, are connected in series, and a magnetic field generation
coil using these drive electrodes as a winding is formed. In
addition, magnetic fields are generated as a current flows in the
drive electrodes TL(0) and TL(2) connected in series, and the
generated magnetic fields are superimposed on each other in an area
of the drive electrode TL(1).
[0468] In the same manner after this, the fifteenth switches are
sequentially turned into the on-state, two drive electrodes are
connected in series, and a current flows in the drive electrodes
connected in series, thereby generating a strong magnetic field. In
addition, a magnetic field generation coil using the drive
electrode TL(5) and the voltage wiring TL(TPL) as a winding is
formed when the fifteenth switch USW6(6) is turned into the
on-state by the selection signal S56 sent from the unit drive
circuit USU(6). In this case, a strong magnetic field is generated
in an area of the drive electrode TL(6).
[0469] Although the description has been given in FIG. 35 regarding
the case where one drive electrode is sandwiched therebetween, the
invention is not limited thereto. For example, two or more drive
electrodes may be sandwiched, or no drive electrode may be
sandwiched therebetween. For example, when the two drive electrodes
are sandwiched therebetween, the fifteenth switch USW6(0) is
connected between the voltage wiring TL(TPH) and the drive
electrode TL(2), and the fifteenth switch USW6(1) is connected
between the drive electrode TL(0) and the drive electrode TL(3). On
the other hand, when no drive electrode is sandwiched therebetween,
the fifteenth switch USW6(0) is connected between the voltage
wiring TL(TPH) and the drive electrode TL(0), and the fifteenth
switch USW6(1) is connected between the drive electrode TL(0) and
the drive electrode TL(1).
[0470] The magnetic field detection coil and the electric field
detection electrode may be provided in the same manner as the fifth
embodiment. In addition, the electric field touch detection can be
realized in the same manner as the fifth embodiment.
[0471] In the sixth embodiment, the voltage wirings TL(TPH) and
TL(TPL), which are arranged outside the display panel 2 along the
sides of the display panel 2, are also used as the winding of the
magnetic field generation coil. Thus, it is possible to detect
touch by a pen even in each part proximate to the side 2-L and the
side 2-R of the display panel 2. Of course, only one of the voltage
wirings may be used as the winding of the magnetic field generation
coil, or the voltage wirings TL(TPH) and TL(TPL) may not
necessarily used as the winding of the magnetic field generation
coil. In addition, the description has been given in FIG. 35 by
exemplifying the magnetic field generation coil having a one-turn
winding, but the magnetic field generation coil may have a winding
with one and half turns or more.
[0472] In the present specification, the drive wiring, for example,
the drive electrode, the signal line or the scan line, which
generates the magnetic field in the magnetic field generation
period TGT, includes a pair of end portions. The other end portion
(or one end portion) out of the pair of end portions is present in
the extending direction of the drive wiring with respect to one end
portion (or the other end portion). The drive signal is supplied to
the one end portion (or the other end portion), and the ground
voltage Vss serving as a reference signal is supplied to the other
end portion (or the one end portion) at the time of generating the
magnetic field. When the one end portion and the other end portion
are regarded as a first area and a second area of the drive wiring,
the drive signal can be regareded as being supplied to the first
area (or the second area) of the drive wiring, and the reference
signal can be regarded as being supplied to the second area (or the
first area) in the magnetic field generation period TGT.
[0473] When FIG. 8 of the first embodiment is exemplified, the
drive wiring which generates the magnetic field correspond to the
drive electrodes TL(0) to TL(p) extending in the row direction in
the magnetic field generation period TGT, and the first area
(second area) is present in the direction extending in the row
direction with respect to the second area (first area). In
addition, when the plurality of drive electrodes TL(0) to TL(p) are
regarded as a plurality of drive wirings, one drive electrode out
of a pair of drive electrodes, which is selected by the selection
signal sent from the unit drive circuit in the magnetic field
generation period TGT, can be regarded as a first drive wiring, and
the other drive electrode can be regarded as a second drive wiring.
In this case, respective one end portions (for example, the first
areas) of the first drive wiring and the second drive wiring are
arranged on the same side (for example, the side 2-L) of the
display panel 2 side, and the respective other end portions (the
second areas) are arranged on the same side (the side 2-R) of the
display panel 2 side. Thus, the respective first areas (one end
portions) of the first drive wiring and the second drive wiring are
proximate to each other, and the respective second areas (the other
end portions) of the first drive wiring and the second drive wiring
are proximate to each other.
[0474] In addition, when one or more drive wirings (the drive
electrode in FIG. 8) are sandwiched between the selected pair of
drive wirings in the magnetic field generation period TGT, the
sandwiched drive wiring(s) can be regarded as a third drive wiring.
Further, when the drive electrodes TL(0) to TL(p) are regarded as
the drive wirings by exemplifying FIG. 8, the signal lines SL(0) to
SL(p), which extend in the column direction to cross the drive
electrodes TL(0) to TL(p), can be regarded as detection wirings. Of
course, the detection wirings are not limited to the signal lines
SL(0) to SL(p) but may be the scan lines GL(0) to GL(p) or the
detection electrodes RL(0) to RL(p).
[0475] It is understood that those skilled in the art can derive
various types of modified examples and corrections in the category
of the idea of the present invention, and these modified example
and corrections are encompassed within the scope of the present
invention.
[0476] Any one obtained when those skilled in the art appropriately
modify the above embodiments by addition, deletion, or design
change of components, or by addition, omission, or condition change
of steps is also encompassed within the scope of the invention as
long as it includes a gist of the invention.
[0477] For example, the description has been given in the
embodiments regarding the case where the common electrodes TL(0) to
TL(p) and the signal lines SL(0) to SL(p) extend in the column
direction and are arranged in the row direction, but the row
direction and the column direction are changed depending on a point
of view. A case where the point of view is changed so that the
common electrodes TL(0) to TL(p) and the signal lines SL(0) to
SL(p) extend in the row direction and are arranged in the column
direction is also included in the scope of the present invention.
In addition, the expression "parallel" used in the present
specification means to extend without intersecting each other from
one end to the other end. Thus, when lines do not intersect each
other from one end to the other end even though a part or the
entire part of one line is provided in the state of being inclined
to the other line, this state is also considered as "parallel" in
the present specification. In addition, the description has been
given in FIG. 18 regarding the example where the drive electrode
except for the drive electrode that generates the electric field is
connected to the voltage wiring VCOM at the time of electric field
touch detection. But, the invention is not limited thereto, and the
drive electrode except for the drive electrode that generates the
electric field may be set to the floating state.
* * * * *